OBJECT DRUGS
PRECIPITANT DRUGS
- Fluvoxamine (Luvox, etc.)
Comment:
Theophylline is metabolized by CYP1A2 and to a lesser extent CYP3A4. Fluvoxamine is a potent inhibitor of CYP1A2, and may produce dramatic increases in theophylline plasma concentrations; theophylline toxicity is likely to occur.
Class 2: Use Only if Benefit Felt to Outweigh Risk
- Use Alternative: Sertraline (Zoloft), fluoxetine (Prozac), venlafaxine (Effexor), paroxetine (Paxil), citalopram (Celexa), and escitalopram (Lexapro) are not known to inhibit CYP1A2. Nefazodone is a potent inhibitor of CYP3A4, and may increase theophylline concentrations, but probably to a lesser extent than fluvoxamine.
- Monitor: Monitor for altered theophylline response if a CYP1A2 inhibitor is initiated, discontinued, or the dose is changed. Evidence of theophylline toxicity includes nausea, vomiting, diarrhea, restlessness, irritability, and insomnia. Higher serum levels can result in cardiac arrhythmias or seizures.