Meprobamate

Products

Meprobamate was commercially available in tablet form (Meprodil, 400 mg). It was approved in many countries in 1957 and was withdrawn from the market on October 31, 2012. The French Medicines Agency revoked the approval back in January 2012 due to the potential adverse effects and toxicity. The European Medicines Agency (EMA) also concluded in January that the benefits of the drug did not outweigh the risks and that meprobamate should be withdrawn from the market throughout the EU.

Structure and properties

Meprobamate (C9H18N2O4, Mr = 218.3 g/mol) is a carbamate. It exists as a white, amorphous or crystalline powder with a typical odor and bitter taste that is sparingly soluble in water.

Effects

Meprobamate (ATC N05BC01) is depressant, muscle relaxant, and anticonvulsant. It is among the oldest synthetic sedatives. Due to poor tolerability and toxicity, meprobamate is controversial. Today, comparatively better-tolerated sedatives such as the benzodiazepines are commercially available.

Indications

For the treatment of anxiety and tension states. Meprobamate has also been used as a muscle relaxant and as a sleep aid.

Contraindications

Meprobamate is contraindicated in hypersensitivity and acute intermittent porphyria. It is teratogenic and should not be used during pregnancy. For complete precautions, see the drug label.

Interactions

Meprobamate is an inducer of CYP3A4 and may cause corresponding drug-drug interactions. Centrally depressant agents and substances, such as narcotics, opioids, sleep aids, and antidepressants, may increase adverse effects.

Adverse effects

The most common possible adverse effects include fatigue, drowsiness, ataxia, headache, dizziness, weakness, paresthesias, paradoxical CNS reactions, euphoria, accommodation disorders, palpitations, rapid pulse, cardiac arrhythmias, syncope, low blood pressure, loss of appetite, nausea, vomiting, diarrhea, and allergic reactions. Meprobamate can be addictive and lead to withdrawal symptoms when rapidly discontinued. Overdose in the gram range manifests similarly to barbiturates and results in dangerous respiratory depression, which can be fatal.