Pharmacokinetically induced benzodiazepine withdrawal.
Pharmacokinetic interactions between medications can have clinically significant effects. Concern usually arises when a medication is added to a continuing regimen, though discontinuation of a medication can also have an impact. A case is presented of a patient who experienced benzodiazepine withdrawal symptoms on discontinuation of nefazodone, an antidepressant that inhibits the cytochrome P450 3A4 isoenzyme. Plasma levels of alprazolam, a substrate for the 3A4 isozyme, fell rapidly when nefazodone was discontinued, presumably because of renewed 3A4 isoenzyme activity. The management of the patient's withdrawal symptoms is described.
Ninan
P T
PT
Mood and Anxiety Disorders Program, Emory University School of Medicine in Atlanta, GA, USA. philninan@learnlink.emory.edu
D000525:Alprazolam / Q000009:adverse effects* / Q000493:pharmacokinetics*; D014151:Anti-Anxiety Agents / Q000009:adverse effects* / Q000493:pharmacokinetics*; D018687:Antidepressive Agents, Second-Generation / Q000009:adverse effects* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D003511:Cyclohexanols / Q000627:therapeutic use; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D016584:Panic Disorder / Q000188:drug therapy; D010879:Piperazines; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology / Q000523:psychology*; D014230:Triazoles / Q000009:adverse effects* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000069470:Venlafaxine Hydrochloride
D014151:Anti-Anxiety Agents; D018687:Antidepressive Agents, Second-Generation; D003511:Cyclohexanols; D010879:Piperazines; D014230:Triazoles; C051752:nefazodone; D000069470:Venlafaxine Hydrochloride; D000525:Alprazolam