Dextromethorphan monoamine oxidase

Dextromethorphan-monoamine oxidase inhibitors Calcium carbonate-tetracycline... 

Sinclair JG. Dextromethorphan-monoamine oxidase inhibitor interaction in rabbits. JPharm Pharmacol 9iy) 25, 803-8,... 

When dextromethorphan is administered with the monoamine oxidase inhibitors (see Chap. 31), patients may experience hypotension, fever, nausea, jerking motions to the leg, and coma... 

Wiley JL, LaVecchia KL, Martin BR, Damaj MI (2002) Nicotine-like discriminative stimulus effects of bupropion in rats. Exp Clin Psychopharmacol 10 129-135 Williams M, Robinson JL (1984) Binding of the nicotinic cholinergic antagonist, dihydro-beta-erythroidine, to rat brain tissue. J Neurosci 4 2906-2911 Witkin JM, Dykstra LA, Carter RB (1982) Acute tolerance to the discriminative stimulus properties of morphine. Pharmacol Biochem Behav 17 223-228 Wooters TE, Bardo MT (2007) The monoamine oxidase inhibitor phenelzine enhances the discriminative stimulus effect of nicotine in rats. Behav Pharmacol 18 601-608 Wright JM Jr, Vann RE, Gamage TE, Damaj MI, WUey JL (2006) Comparative effects of dextromethorphan and dextrorphan on nicotine discrimination in rats. Pharmacol Biochem Behav 85 507-513... 

Dmg-induced serotonin syndrome is generally mild and resolves when the offending drugs are stopped. However, it can be severe and deaths have occurred. A large number of drugs have been implicated including tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), selective serotonin re-uptake inhibitors (SSRIs), pethidine, lithium, and dextromethorphan. The most severe type of reaction has occurred with the combination of selective serotonin re-uptake inhibitors and monoamine oxidase inhibitors. Both non-selective MAOIs such as phenelzine and selective MAOIs such as moclobemide and selegiline have been implicated. 

Dextromethorphan hydrobromide is the D-isomer of levorphanol. It lacks CNS activity but acts at the cough center in the medulla to produce an antitussive effect. It is half as potent as codeine as an antitussive. Anecdotal reports of abuse exist, but studies of abuse potential are lacking. It has few side effects but does potentiate the activity of monoamine oxidase inhibitors, leading to hypotension and infrequently coma. Dextromethorphan is often combined in lozenges with the local anesthetic benzocaine, which blocks pain from throat irritation due to coughing. 

Contraindications Coadministration with monoamine oxidase inhibitors (MAOls), hypersensitivity to dextromethorphan or its components... 

The opioid derivatives most commonly used as antitussives are dextromethorphan, codeine, levopropoxyphene, and noscapine (levopropoxyphene and noscapine are not available in the USA). They should be used with caution in patients taking monoamine oxidase inhibitors (see Table 31-5). Antitussive preparations usually also contain expectorants to thin and liquefy respiratory secretions. Importantly, due to increasing reports of death in young children taking dextromethorphan in formulations of over-the-counter "cold/cough" medications, its use in children less than 6 years of age has been banned by the FDA. Moreover, due to variations in the metabolism of codeine, its use for any purpose in young children is being reconsidered. 

Patients should not use dextromethorphan if they are taking any drug in the class known as monoamine oxidase inhibitors (MAOI), including phenelzine (Nardil), isocarboxazid (Marplan), and tranylcypromine (Parnate), which are used in the treatment of depression. The combination of MAOIs with dextromethorphan can lead to toxic levels of dextromethorphan in the blood. 

The drugs that can cause a serotonin syndrome when they are combined with SSRIs include monoamine oxidase inhibitors (including reversible inhibitors of monoamine oxidase types A and B), dextromethorphan,... 

A possible interaction between dextromethorphan and the monoamine oxidase inhibitor isocarboxazid has been described, with myoclonic jerks, choreoathetoid movements, and marked urinary retention (58). 

Sovner R, Wolfe J. Interaction between dextromethorphan and monoamine oxidase inhibitor therapy with isocarboxazid. N Engl J Med 1988 319(25) 1671. 

The risk of serotonin syndrome may be increased shortly after dosage increases of SSRIs or when drug interactions increase serotonin activity. Concomitant or proximal use of SSRIs, tricyclic antidepressants, or monoamine oxidase inhibitors may cause serotonin syndrome. Further, the addition of certain drugs, such as tryptophan, dextromethorphan, cocaine, or sympathomimetics, to SSRI therapy may increase the risk of developing serotonin syndrome." ... 

Unlike the combined monoamine oxidase inhibitor (MAOl) and dextromethorphan... 

Dextromethorphan is contraindicated in patients taking selective serotonin reuptake inhibitors and monoamine oxidase inhibitors. 

Concomitant use of monoamine oxidase inhibitors has caused toxicity leading to coma and death. There are serious life-threatening serotonergic syndrome interactions between dextromethorphan and serotonin reuptake inhibitors. Alcohol and other CNS depressant drugs should be avoided when taking dextromethorphan. 

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