Cold Medications Safe With Lithium

Lithium is a widely utilized and effective medication for the treatment of a variety of psychiatric conditions. These conditions include:

• Bipolar Disorder
• Mania

However, lithium is classified as a 'narrow therapeutic index' drug. Doses of lithium resulting in therapeutic or toxic concentrations in the blood are close. Care must be taken with initial dosing and dose titration.

Due to the risk of toxicity, close monitoring of lithium concentrations is necessary when initiating therapy and routinely for the duration of treatment. In fact, the prescribing information for lithium has a boxed warning stating the following:

"Lithium toxicity is closely related to serum lithium concentrations, and can occur at doses close to therapeutic concentrations. Facilities for prompt and accurate serum lithium determinations should be available before initiating therapy."

For some individuals, lithium can be a particularly difficult drug to avoid adverse effects on as a variety of common conditions can cause fluctuating lithium levels, which could result in toxicity. These conditions include:

• Urinary retention
• Hyponatremia (low sodium levels)
• Dehydration
• Infection

Additionally, it is important to be aware of clinically significant drug interactions that can affect lithium levels. Since you are interested in over-the-counter cold medications, these are discussed below.

Cold Medications To Avoid With Lithium

NSAIDs

Non-steroidal anti-inflammatory drugs should generally be avoided with lithium. Over-the-counter NSAIDs include:

• Advil (Ibuprofen)
• Motrin (Ibuprofen)
• Aleve (Naproxen)
• Aspirin

NSAIDs decrease blood flow in the kidneys, which results in decreased lithium clearance and increased serum lithium concentrations. This increases the risk of side effects.

A variety of studies have shown that lithium toxicity has resulted from interactions between an NSAID and lithium. One study found that both indomethacin and piroxicam have been reported to significantly increase steady-state plasma lithium concentrations.

There is also evidence that other NSAIDs, including the selective cyclooxygenase-2 (COX-2) inhibitors (e.g. Celebrex), have the same effect.

There aren't many studies looking specifically at over-the-counter NSAIDs (like ibuprofen), but they should nonetheless be avoided.

Caffeine

Although not traditionally seen as a 'cold' medication, caffeine is a common ingredient in many over-the-counter analgesics, including Excedrin.

Caffeine appears to reduce serum lithium concentrations. Therefore, ingesting excess caffeine can decrease the effects of lithium.

However, and this is important to note, lithium adverse reactions have also been noted to increase simultaneously with a reduction in caffeine intake.

One study noted that in 11 coffee-drinking patients stabilized on lithium, serum lithium concentrations increased during 2 weeks when coffee was withheld and fell when coffee was resumed.

It is therefore recommended to keep your caffeine intake consistent when taking lithium.

Herbal Medications

Lithium should be avoided with many herbal medications. These include:

• Caffeine-containing products (e.g. guarana, green tea, cola nut).
• Those with diuretic effects (e.g. agrimony, artichoke, buchu, burdock, celery, corn silk, guaiac wood, squill and uva ursi). Changing the fluid balance in our bodies can alter lithium levels.
• Those with serotonergic effects (e.g. 5-hydroxytryptophan, Hawaiian baby woodrose, L-tryptophan, S-adenosylmethionine, and St. John's wort). Serotonin and lithium are discussed more below.

Cold Medications To Use Caution With

Dextromethorphan

Dextromethorphan, a commonly used anti-tussive, can have serotonergic effects (i.e. can increase serotonin levels). Lithium can also increase serotonin levels, but only to a mild degree.

Taking multiple drugs that have serotonergic effects can increase the risk of developing serotonin syndrome. Serotonin syndrome is characterized by the rapid development of:

• Hyperthermia
• High blood pressure
• Mental status changes

Serotonin syndrome with lithium is thought to be rare but is extremely serious if it occurs.

Most reported cases of serotonin syndrome with lithium have only occurred in individuals on multiple prescription serotonergic drugs. Nevertheless, it is important to be aware of and you should discuss the use of dextromethorphan with your doctor prior to using it.

Sedating Antihistamines

While there is no drug-drug interaction with lithium and sedating antihistamines (like Benadryl), they can cause additive sedation and drowsiness. Therefore, caution is advisable during concurrent use of both.

Cold Medications Safe With Lithium

Tylenol

Tylenol (acetaminophen) is considered a safe analgesic to take with lithium. There are no known drug interactions.

Mucinex

Mucinex (guaifenesin) is a commonly used expectorant that has few drug interactions. It is considered safe to take with lithium.

Sudafed

Sudafed (pseudoephedrine) is a nasal decongestant that has no known drug interaction with lithium. Additionally, Sudafed PE, which contains phenylephrine, is not known to interact with lithium.

Final Words

It is always a good idea to check into potential drug interactions before taking over-the-counter medication. This is especially true with a drug like lithium, which has a narrow range of safety and efficacy.

Several are considered safe (e.g. Tylenol, Mucinex, and Sudafed) but several others should be avoided (e.g. NSAIDs). Be sure to ask your doctor or local pharmacist about potential drug interactions with any over-the-counter product you are looking at purchasing.