HomeNDC LookupIngredientsGuanfacine › 00591-0453-00
Guanfacine 2 mg Tablet, 77,000-count — NDC 00591-0453-00 package photo

Guanfacine 2 mg Tablet, 77,000-count

by Actavis Pharma, Inc. · 77000 TABLET in 1 BAG (0591-0453-00)
NDC 00591-0453-00
🏷️ FDA NDC (as labeled) 0591-0453-00 billing pads the labeler segment with a zero
This package
Contains77,000-count Pack sizes3 compare ↓
On market Non-controlled
🗂️ Data synced Sep 17, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

🆔 Identity & classification

FDA NDC (as labeled) 0591-0453-00
Product NDC 0591-0453
11-digit billing NDC 00591045300
SPL Set ID a81b956b-f004-4426-ba20-375ccf21eb71
DEA schedule Non-controlled
Marketing category DRUG FOR FURTHER PROCESSING
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 1995-10-17
Dosage form TABLET
Substance GUANFACINE HYDROCHLORIDE
GPI-14 36201025100330
GPI class guanFACINE HCl
GCN Seq No 011984
GCN 32481
HICL code 000120
Ingredient (HICL) Guanfacine Hcl
HIC1 code A
Therapeutic class — broad (HIC1) Cardiovascular System
HIC2 code A4
Therapeutic class — intermediate (HIC2) Antihypertensives
HIC3 code A4B
Therapeutic class — specific (HIC3) Antihypertensives, Sympatholytic
AHFS code 24:24.00.00
AHFS class Central Alpha-Agonists
FDB label name GUANFACINE 2 MG TABLET
FDB brand name Guanfacine Hcl
Legend status F — Federal legend — prescription drug or device
Why two NDCs? The FDA registers this code as 0591-0453-00 — a 4-4-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the labeler segment → 00591-0453-00. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏭 Manufacturer & labeler

LabelerActavis Pharma, Inc.
Labeler code00591
First marketedOct 1995
Product typeDrug For Further Processing
Portfolio324 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name GUANFACINE 2 MG TABLET Ingredient Guanfacine Hcl
📗 Our plain-language guide HelloPharmacist
  • It's used for both, depending on which form you have. The regular (immediate-release) tablet is prescribed for high blood pressure. The extended-release version — brand name Intuni...
  • What is guanfacine actually used for — is it for ADHD or blood pressure?
  • No, Intuniv is not a stimulant at all. It works on a different part of the brain than medications like Adderall or Ritalin. That's actually one reason it's sometimes used alongside...
  • My child takes Intuniv for ADHD — is it a stimulant?
📖 Read our full Guanfacine guide →
1
Nutrient depletion considerations

Guanfacine may be associated with lower levels of 1 nutrient — worth a chat with your pharmacist, not a cause for alarm.

An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

💊 What it looks like

Color pink / red
ShapeRound
ImprintWATSON;453
Size8 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII 3SY5LH9PMK
    Anhydrous lactose is a milk sugar with no water content. It acts as a filler and binder in tablets and capsules, adding bulk and helping ingredients stick together.
  • UNII OP1R32D61U
    Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
  • UNII CQ3XH3DET6
    D&C Yellow No. 10 Aluminum Lake is a yellow colorant made by combining a dye with aluminum salts. It's used in medicines to add color for product identification and visual appeal.
  • UNII WZB9127XOA
    A synthetic red dye used to color medications and make them easier to identify. It serves as a colorant in tablets, capsules, and liquid formulations.
  • UNII FZ989GH94E
    Povidone is a synthetic polymer made from a plastic-like material. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in your stomach so the medicine can be absorbed.
  • UNII 4ELV7Z65AP
    Stearic acid is a fatty acid derived from plant or animal sources. It acts as a binder and lubricant in tablets and capsules, helping them hold together and flow smoothly during manufacturing.

6 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMedingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eachPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Try another pack size: 100 tablets 92304 tablets
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Guanfacine Hydrochloride 2 mg 24979-0199-01 TWi 100 tablets $0.272 AB Availability likely
Guanfacine 2 mg 27241-0243-01 Ajanta 100 tablets $0.272 AB Availability likely
Guanfacine Hydrochloride 2 mg 29300-0459-01 Unichem 100 tablets $0.272 AB Availability likely
Guanfacine 2 mg 42806-0296-01 Epic 100 tablets $0.272 AB Availability likely
Guanfacine Hydrochloride 2 mg 50268-0374-15 AvPAK 50 tablets $0.272 AB Availability likely
Guanfacine Hydrochloride 2 mg 53746-0713-01 Amneal 100 tablets $0.272 AB Availability likely
Guanfacine 2 mg 59651-0841-01 Aurobindo 100 tablets $0.272 AB Availability likely
Guanfacine Hydrochloride 2 mg 62135-0728-90 Chartwell 90 tablets $0.272 AB Availability likely
Guanfacine Hydrochloride 2 mg 70700-0302-01 XIROMED, 100 tablets $0.272 AB Availability likely
Guanfacine 2 mg 72319-0019-04 i3 100 tablets $0.272 AB Availability likely
Guanfacine 2 mgthis 00591-0453-00 Actavis 77000 tablets FDA listed
Guanfacine Hydrochloride 2 mg 65162-0713-03 Amneal 30 tablets AB FDA listed
Guanfacine 2 mg 67046-1655-03 Coupler 30 tablets AB FDA listed
Guanfacine Hydrochloride 2 mg 70518-3516-00 REMEDYREPACK 30 tablets AB FDA listed
Guanfacine 2 mg 70518-4488-00 REMEDYREPACK 30 tablets AB FDA listed
Guanfacine 2 mg 70518-4564-00 REMEDYREPACK 30 tablets AB FDA listed
Guanfacine Hydrochloride 2 mg 72603-0269-01 NORTHSTAR 100 tablets AB FDA listed
Guanfacine 2 mg 72888-0124-00 Advagen 1000 tablets AB FDA listed
Guanfacine 2 mg 73141-0019-04 A2A 100 tablets AB FDA listed
About this product: other versions of the same ingredient, strength and form are listed above, least expensive first, with FDA equivalence ratings where available.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
1995
On the market since
Oct 1995
📍
2026
Currently FDA-listed
31 years listed
🔓
·
Generic versions listed
see equivalents
Generic appears available

FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available — see Therapeutic equivalents.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

💊 Medicaid utilization by pack size

Medicaid (SDUD) totals over the four most recent reported quarters for every package size of this drug — handy when a specific package (e.g. a starter/titration pack) carries little or no Medicaid volume on its own.
100 tablets00591-0453-01 32,739 Rx · $699,870
92304 tablets00591-0453-77 No Medicaid data
Drug total (last 4 qtrs): 32,739 Rx · 1,512,963 units · $699,870 gross reimbursed
Tap a pack size to open its page. Source: CMS State Drug Utilization Data, last 4 quarters.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for Guanfacine — the ingredient across all brands.

Top reported reactions

Somnolence471
Aggression388
Fatigue351
Hypotension299
Dizziness291
Insomnia288
Headache283

Reporter sex

0 reports

Serious outcomes

Hospitalization1,909
Reports over time (by year) — tap or hover for the count & year
2021 2022 2024 2026 741 415
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
00591-0453-01 100 TABLET in 1 BOTTLE (0591-0453-01) $0.2721 / ea $27.21 1995-10-17 Active
00591-0453-00 You're viewing this 77000 TABLET in 1 BAG (0591-0453-00) Active
00591-0453-77 92304 TABLET in 1 CONTAINER (0591-0453-77) Active

You're viewing one of 3 pack sizes for this product.

This pack shows little to no recent Medicaid volume — the 100 tablets pack carries most fills. See all packs ↓

Pack size FAQ

What quantity is in NDC 00591-0453-00?
NDC 00591-0453-00 is a 77,000-count package — 77000 tablet in 1 bag.
What is the difference between NDC 00591-0453-00 and NDC 00591-0453-01?
Both are Guanfacine 2 mg Tablet — the drug itself is identical. NDC 00591-0453-00 is the 77,000-count package, while NDC 00591-0453-01 is the 100 tablets package.
What NDC number is used to bill for this package of Guanfacine 2 mg Tablet?
Bill NDC 00591-0453-00 — the 11-digit billing format is 00591045300. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.

🧭 About this NDC listing & data coverage

Listed for further processing / repackaging

What "drug for further processing" means

FDA lists this package under the "drug for further processing" marketing category: Actavis Pharma, Inc. supplies it to other companies for further processing or repackaging (blister cards that are later repackaged or co-packaged are a common example). The units themselves are a finished dosage form — which is why pricing or Medicaid data can still appear — but this exact package code may not be the presentation a retail pharmacy dispenses.

What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) ✓ Available
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data — Not published for this NDC Applies only to products approved under an NDA/ANDA; many listings are out of scope.
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Is this NDC FDA-approved?
An NDC listing does not by itself establish FDA approval — the NDC Directory records that a product is listed with FDA, not that it was reviewed and approved. This listing's marketing category is "Drug For Further Processing". Products approved under an application carry an NDA, ANDA, or BLA number.
Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 0591-0453-00, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 00591-0453-00, written without dashes as 00591045300. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 00591-0453-00, the first segment (00591) is the labeler code FDA assigned to Actavis Pharma, Inc.; the middle segment (0453) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (00) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Actavis Pharma, Inc.. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 2 other package presentations of this same product, including 100 tablets (00591-0453-01), 92304 tablets (00591-0453-77). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Actavis Pharma, Inc. is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full FDA label FDA SPL

The complete FDA label for this product, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage 30 words

INDICATIONS AND USAGE Guanfacine tablets, USP are indicated in the management of hypertension. Guanfacine tablets, USP may be given alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.

⏱️ Dosage and Administration 147 words

DOSAGE AND ADMINISTRATION The recommended initial dose of guanfacine hydrochloride when given alone or in combination with another antihypertensive drug is 1 mg daily given at bedtime to minimize somnolence. If after 3 to 4 weeks of therapy 1 mg does not give a satisfactory result, a dose of 2 mg may be given, although most of the effect of guanfacine is seen at 1 mg (see CLINICAL PHARMACOLOGY ). Higher daily doses have been used, but adverse reactions increase significantly with doses above 3 mg/day.

The frequency of rebound hypertension is low, but it can occur. When rebound occurs, it does so after 2 to 4 days, which is delayed compared with clonidine hydrochloride. This is consistent with the longer half-life of guanfacine.

In most cases, after abrupt withdrawal of guanfacine, blood pressure returns to pretreatment levels slowly (within 2 to 4 days) without ill effects.

Contraindications 13 words

CONTRAINDICATIONS Guanfacine tablets are contraindicated in patients with known hypersensitivity to guanfacine hydrochloride.

🤒 Adverse Reactions ~3 min read

ADVERSE REACTIONS Adverse reactions noted with guanfacine are similar to those of other drugs of the central α 2 -adrenoreceptor agonist class: dry mouth, sedation (somnolence), weakness (asthenia), dizziness, constipation, and impotence. While the reactions are common, most are mild and tend to disappear on continued dosing. Skin rash with exfoliation has been reported in a few cases; although clear cause and effect relationships to guanfacine could not be established, should a rash occur, guanfacine should be discontinued and the patient monitored appropriately.

In the dose-response monotherapy study described under CLINICAL PHARMACOLOGY , the frequency of the most commonly observed adverse reactions showed a dose relationship from 0.5 to 3 mg as follows: Adverse Placebo 0.5 mg 1 mg 2 mg 3 mg Reaction n=59 n=60 n=61 n=60 n=59 Dry Mouth 0% 10% 10% 42% 54% Somnolence 8% 5% 10% 13% 39% Asthenia 0% 2% 3% 7% 3% Dizziness 8% 12% 2% 8% 15% Headache 8% 13% 7% 5% 3% Impotence 0% 0% 0% 7% 3% Constipation 0% 2% 0% 5% 15% Fatigue 2% 2% 5% 8% 10% The percent of patients who dropped out because of adverse reactions are shown below for each dosage group.

Placebo 0.5 mg 1 mg 2 mg 3 mg Percent dropouts 0% 2% 5% 13% 32% The most common reasons for dropouts among patients who received guanfacine were dry mouth, somnolence, dizziness, fatigue, weakness, and constipation. In the 12-week, placebo-controlled, dose-response study of guanfacine administered with 25 mg chlorthalidone at bedtime, the frequency of the most commonly observed adverse reactions showed a clear dose relationship from 0.5 to 3 mg as follows: Placebo 0.5 mg 1 mg 2 mg 3 mg Adverse Reaction n = 73 n = 72 n = 72 n = 72 n = 72 Dry Mouth 5 (7%) 4 (5%) 6 (8%) 8 (11%) 20 (28%) Somnolence 1 (1%) 3 (4%) 0 (0%) 1 (1%) 10 (14%) Asthenia 0 (0%) 2 (3%) 0 (0%) 2 (2%) 7 (10%) Dizziness 2 (2%) 1 (1%) 3 (4%) 6 (8%) 3 (4%) Headache 3 (4%) 4 (3%) 3 (4%) 1 (1%) 2 (2%) Impotence 1 (1%) 1 (0%) 0 (0%) 1 (1%) 3 (4%) Constipation 0 (0%) 0 (0%) 0 (0%) 1 (1%) 1 (1%) Fatigue 3 (3%) 2 (3%) 2 (3%) 5 (6%) 3 (4%) There were 41 premature terminations because of adverse reactions in this study.

The percent of patients who dropped out and the dose at which the dropout occurred were as follows: Dose: Placebo 0.5 mg 1 mg 2 mg 3 mg Percent dropouts 6.9% 4.2% 3.2% 6.9% 8.3% Reasons for dropouts among patients who received guanfacine were: somnolence, headache, weakness, dry mouth, dizziness, impotence, insomnia, constipation, syncope, urinary incontinence, conjunctivitis, paresthesia, and dermatitis. In a second 12-week placebo-controlled combination therapy study in which the dose could be adjusted upward to 3 mg per day in 1-mg increments at 3-week intervals, i.e., a setting more similar to ordinary clinical use, the most commonly recorded reactions were: dry mouth, 47%; constipation, 16%; fatigue, 12%; somnolence, 10%; asthenia, 6%; dizziness, 6%; headache, 4%; and insomnia, 4%.

Reasons for dropouts among patients who received guanfacine were: somnolence, dry mouth, dizziness, impotence, constipation, confusion, depression, and palpitations. In the clonidine/guanfacine comparison described in CLINICAL PHARMACOLOGY , the most common adverse reactions noted were as follows: Guanfacine Clonidine Adverse Reactions (n=279) (n=278) Dry Mouth 30% 37% Somnolence 21% 35% Dizziness 11% 8% Constipation 10% 5% Fatigue 9% 8% Headache 4% 4% Insomnia 4% 3% Adverse reactions occurring in 3% or less of patients in the three controlled trials of guanfacine with a diuretic were: Cardiovascular - bradycardia, palpitations, substernal pain Gastrointestinal - abdominal pain, diarrhea, dyspepsia, dysphagia, nausea CNS - amnesia, confusion, depression, insomnia, libido decrease ENT disorders - rhinitis, taste perversion, tinnitus Eye disorders - conjunctivitis, iritis, vision disturbance Musculoskeletal - leg cramps, hypokinesia Respiratory - dyspnea Dermatologic - dermatitis, pruritus, purpura, sweating Urogenital - testicular disord…

🔄 Drug Interactions 95 words

Drug Interactions: The potential for increased sedation when guanfacine is given with other CNS- depressant drugs should be appreciated. The administration of guanfacine concomitantly with a known microsomal enzyme inducer (phenobarbital or phenytoin) to two patients with renal impairment reportedly resulted in significant reductions in elimination half-life and plasma concentration. In such cases, therefore, more frequent dosing may be required to achieve or maintain the desired hypotensive response.

Further, if guanfacine is to be discontinued in such patients, careful tapering of the dosage may be necessary in order to avoid rebound phenomena (see Rebound above).

🔄 Drug / Laboratory Test Interactions 16 words

Drug/Laboratory Test Interactions: No laboratory test abnormalities related to the use of guanfacine have been identified.

🧒 Pediatric Use 93 words

Pediatric Use: Safety and effectiveness in children under 12 years of age have not been demonstrated. Therefore, the use of guanfacine in this age group is not recommended. There have been spontaneous postmarketing reports of mania and aggressive behavioral changes in pediatric patients with attention- deficit hyperactivity disorder (ADHD) receiving guanfacine.

The reported cases were from a single center. All patients had medical or family risk factors for bipolar disorder. All patients recovered upon discontinuation of guanfacine HCl.

Hallucinations have been reported in pediatric patients receiving guanfacine for treatment of attention-deficit hyperactivity disorder.

🧓 Geriatric Use 87 words

Geriatric Use: Clinical studies of guanfacine did not include sufficient numbers of subjects aged 65 and over to determine whether they responded differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy (see CLINICAL PHARMACOLOGY: Pharmacokinetics ).

🆘 Overdosage 175 words

OVERDOSAGE Signs and Symptoms: Drowsiness, lethargy, bradycardia and hypotension have been observed following overdose with guanfacine. A 25-year-old female intentionally ingested 60 mg. She presented with severe drowsiness and bradycardia of 45 beats/minute.

Gastric lavage was performed and an infusion of isoproterenol (0.8 mg in 12 hours) was administered. She recovered quickly and without sequelae. A 28-year-old female who ingested 30-40 mg developed only lethargy, was treated with activated charcoal and a cathartic, was monitored for 24 hours, and was discharged in good health.

A 2-year-old male weighing 12 kg who ingested up to 4 mg of guanfacine developed lethargy. Gastric lavage (followed by activated charcoal and sorbitol slurry via NG tube) removed some tablet fragments within 2 hours after ingestion, and vital signs were normal. During 24-hour observation in ICU, systolic pressure was 58 and heart rate 70 at 16 hours post-ingestion.

No intervention was required, and child was discharged fully recovered the next day. Treatment of Overdosage: Gastric lavage and supportive therapy as appropriate. Guanfacine is not dialyzable in clinically significant amounts (2.4%).

🧬 Clinical Pharmacology ~3 min read

CLINICAL PHARMACOLOGY Guanfacine hydrochloride is an orally active antihypertensive agent whose principal mechanism of action appears to be stimulation of central α 2 -adrenergic receptors. By stimulating these receptors, guanfacine reduces sympathetic nerve impulses from the vasomotor center to the heart and blood vessels. This results in a decrease in peripheral vascular resistance and a reduction in heart rate.

The dose-response relationship for blood pressure and adverse effects of guanfacine given once a day as monotherapy has been evaluated in patients with mild to moderate hypertension. In this study patients were randomized to placebo or to 0.5 mg, 1 mg, 2 mg, 3 mg, or 5 mg of guanfacine. Results are shown in the following table.

A useful effect was not observed overall until doses of 2 mg were reached, although responses in white patients were seen at 1 mg; 24 hour effectiveness of 1 mg to 3 mg doses was documented using 24 hour ambulatory monitoring. While the 5 mg dose added an increment of effectiveness, it caused an unacceptable increase in adverse reactions. Mean Changes (mm Hg) from Baseline in Seated Systolic and Diastolic Blood Pressure for Patients Completing 4 to 8 Weeks of Treatment with Guanfacine Monotherapy Mean Change S/D* Seated n= (range) Placebo 0.5 mg 1 mg 2 mg 3 mg 5 mg *S/D = Systolic/diastolic blood pressure White Patients 11-30 -1/-5 -6/-8 -8/-9 -12/-11 -15/-12 -18/-16 Black Patients 8-28 -3/-5 0/-2 -3/-5 -7/-7 -8/-9 -19/-15 Controlled clinical trials in patients with mild to moderate hypertension who were receiving a thiazide-type diuretic have defined the dose-response relationship for blood pressure response and adverse reactions of guanfacine given at bedtime and have shown that the blood pressure response to guanfacine can persist for 24 hours after a single dose.

In the 12-week placebo-controlled dose-response study, patients were randomized to placebo or to doses of 0.5, 1, 2, and 3 mg of guanfacine, in addition to 25 mg chlorthalidone, each given at bedtime. The observed mean changes from baseline, tabulated below, indicate the similarity of response for placebo and the 0.5 mg dose. Doses of 1, 2, and 3 mg resulted in decreased blood pressure in the sitting position with no real differences among the three doses.

In the standing position, there was some increase in response with dose. Mean Decreases (mm Hg) in Seated and Standing Blood Pressure for Patients Treated with Guanfacine in Combination with Chlorthalidone Mean Change n= Placebo 63 0.5 mg 63 1 mg 64 2 mg 58 3 mg 59 *S/D = Systolic/diastolic blood pressure S/D* Seated -5/-7 -5/-6 -14/-13 -12/-13 -16/-13 S/D* Standing -3/-5 -5/-4 -11/-9 -9/-10 -15/-12 While most of the effectiveness of guanfacine in combination (and as monotherapy in white patients) was present at 1 mg, adverse reactions at this dose were not clearly distinguishable from those associated with placebo.

Adverse reactions were clearly present at 2 and 3 mg (see ADVERSE REACTIONS ). In a second 12-week placebo-controlled study of 1, 2, or 3 mg of guanfacine hydrochloride administered with 25 mg of chlorthalidone once daily, a significant decrease in blood pressure was maintained for a full 24 hours after dosing. While there was no significant difference between the 12 and 24 hour blood pressure readings, the fall in blood pressure at 24 hours was numerically smaller, suggesting possible escape of blood pressure in some patients and the need for individualization of therapy.

In a double-blind, randomized trial, either guanfacine or clonidine was given at recommended doses with 25 mg chlorthalidone for 24 weeks and then abruptly discontinued. Results showed equal degrees of blood pressure reduction with the two drugs and there was no tendency for blood pressures to increase despite maintenance of the same daily dose of the two drugs. Signs and symptoms of rebound phenomena were infrequent upon discontinuation of either drug.

Abrupt withdrawal of clonidine produced a rap…

📦 How Supplied / Storage and Handling 132 words

HOW SUPPLIED Guanfacine tablets, USP are available in the following dosing strengths (expressed in equivalent amounts of guanfacine): Guanfacine tablets, USP 1 mg, are pink, round tablets, debossed with WATSON 444 on one side and plain on the other side and are available in bottles of 100 (NDC 0591-0444-01). Guanfacine tablets, USP 2 mg, are peach, round tablets, debossed with WATSON 453 on one side and plain on the other side and are available in bottles of 100 (NDC 0591-0453-01). Bottles of 100 tablets are supplied with child-resistant closures.

Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Dispense in a tight, light-resistant container. Manufactured In India By: Watson Pharma Private Limited Verna, Salcette Goa 403 722 INDIA Manufactured For: Teva Pharmaceuticals Parsippany, NJ 07054 Rev.

A 10/2023

📋 Description 126 words

DESCRIPTION Guanfacine hydrochloride, USP is a centrally acting antihypertensive with α 2 -adrenoceptor agonist properties in tablet form for oral administration. The chemical name of guanfacine hydrochloride, USP is N -Amidino-2-(2,6-dichlorophenyl) acetamide monohydrochloride and its molecular weight is 282.55. Its structural formula is: Guanfacine hydrochloride, USP is a white to off-white powder; sparingly soluble in water and alcohol and slightly soluble in acetone.

Each tablet, for oral administration, contains guanfacine hydrochloride, USP equivalent to 1 mg or 2 mg guanfacine. The tablets contain the following inactive ingredients: 1 mg - anhydrous lactose, FD&C Red #40 Aluminum Lake, microcrystalline cellulose, povidone, stearic acid. 2 mg - anhydrous lactose, D&C Yellow #10 Aluminum Lake, FD&C Red #40 Aluminum Lake, microcrystalline cellulose, povidone, stearic acid.

Guanfacine hydrochloride chemical structure

💬 Information for Patients 61 words

Information for Patients: Patients who receive guanfacine should be advised to exercise caution when operating dangerous machinery or driving motor vehicles until it is determined that they do not become drowsy or dizzy from the medication. Patients should be warned that their tolerance for alcohol and other CNS depressants may be diminished. Patients should be advised not to discontinue therapy abruptly.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.