Clindamycin and Doxacurium: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Clindamycin
Doxacurium
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
These two medicines can add up in a way you should know about. Doxacurium is a muscle relaxer used during surgery to keep your muscles still, including the muscles you breathe with. Clindamycin is an antibiotic that, on its own, can also make muscles a little weaker.
When they are used together, the muscle-relaxing effect can become stronger and last longer than expected, especially with higher doses of clindamycin. This mostly matters in the hospital, where your care team is right there watching you. They can adjust the muscle relaxer dose and support your breathing if needed, so this is very manageable.
Effect: Enhanced and prolonged neuromuscular blockade via additive mechanisms. Clindamycin has intrinsic neuromuscular-blocking activity (pre- and postsynaptic effects plus direct action on muscle contractility) that adds to the nondepolarizing blocker doxacurium.
- Direction: Increased/prolonged blockade (potentiation), dose-dependent with clindamycin.
- Onset: Rapid.
- Evidence: Theoretical; additive PD mechanism.
- Management: Monitor neuromuscular function closely (train-of-four). Doxacurium dose may need reduction and individualization. Anticipate the possible need for postoperative respiratory support and adequate reversal/recovery before extubation.
Neither agent is enzyme-dependent here; this is a pharmacodynamic, not metabolic, interaction.
What happens
Enhanced and prolonged neuromuscular blockade
Interaction Deep Dive
When clindamycin is given together with nondepolarizing muscle relaxants, the result may be an exaggerated neuromuscular blockade, an effect that is more likely at elevated clindamycin doses1234. This clindamycin effect may arise through a combination of presynaptic and postsynaptic activity, along with a direct influence on muscle contractility.
Why it happens (mechanism)
Additive effects
How to manage this interaction
This interaction is handled in a controlled setting (surgery or hospital), where your team is already monitoring your muscles and breathing closely.
- Keep both as prescribed unless your team tells you otherwise; this is managed for you.
- Your care team may monitor your muscle recovery and breathing more closely after anesthesia.
- The doxacurium dose may be adjusted and individualized by your anesthesia team.
- They will anticipate the need for breathing support if the blockade lasts longer than usual.
If you take clindamycin at home and are heading for surgery, mention it to your surgeon, anesthesiologist, or pharmacist.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A 58-year-old woman with severe rheumatoid arthritis underwent wrist arthrodesis while under general anesthesia. She received a small defasciculating dose of tubocurarine 3 mg together with fentanyl 1.5 mcg/kg intravenously (IV). Induction of anesthesia was accomplished with thiopentone 4 mg/kg and succinylcholine 1.5 mg/kg, and it was maintained using nitrous oxide in oxygen along with isoflurane. Complete recovery of neuromuscular function was seen following the succinylcholine injection. At that time, clindamycin phosphate 2400 mg IV was administered; this represented an erroneous overdose because 600 mg had been ordered. Following the operation, the patient did not attempt any spontaneous breathing and failed to respond to painful stimulation. She received calcium chloride, edrophonium, atropine, and neostigmine, with minimal effect. Nine hours after surgery the patient coughed and the train-of-four (TOF) had returned to 1.0. Two hours afterward, she was extubated and spontaneous respiration began. The authors proposed that clindamycin produced muscle relaxation chiefly through a direct effect on contractility, though some pre-synaptic effects were also considered to occur 1.
Common questions
Can I take Clindamycin and Doxacurium together?
Clindamycin can make the muscle relaxer doxacurium work stronger and longer, so anesthesia teams monitor breathing and may lower the doxacurium dose. This is a manageable, hospital-based concern. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clindamycin and Doxacurium interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How is the Clindamycin and Doxacurium interaction managed?
This interaction is handled in a controlled setting (surgery or hospital), where your team is already monitoring your muscles and breathing closely. Keep both as prescribed unless your team tells you otherwise; this is managed for you. Your care team may monitor your muscle recovery and breathing more closely after anesthesia. The doxacurium dose may be adjusted and individualized by your anesthes… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Clindamycin or Doxacurium need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (4)
- Al Ahdal O & Bevan DR: Clindamycin-induced neuromuscular blockade. Can J Anaesth 1995; 42:614-617. PubMed
- Ostergaard D, Engbaek J, & Viby-Mogensen J: Adverse reactions and interactions of the neuromuscular blocking drugs. Med Toxicol Adverse Drug Exp 1989; 4:351-368. PubMed
- Rubbo JT, Gergis SD, & Sokoll MD: Comparative neuromuscular effects of lincomycin and clindamycin. Anesth Analg 1977; 56:329-332. PubMed
- Fogdall RP & Miller RD: Prolongation of a pancuronium-induced neuromuscular blockade by clindamycin. Anesthesiology 1974; 41:407-408. PubMed
Keep reading about Clindamycin
Keep reading about Doxacurium
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