Drug Interactions with Smoking

Question 1

PHARMACOKINETIC DRUG INTERACTIONS with SMOKING

Answer 1

Drugs that may have a decreased effect due to induction of CYP1A2:

• Bendamustine
• Caffeine
• Clozapine
• Erlotinib
• Haloperidol
• Olanzapine
• Riociguat
• Ropinirole
• Tacrine
• Tasimelteon
• Theophylline
• Fluvoxamine
• Irinotecan

*Smoking cessation with reverse these effects

Question 2

TOBACCO SMOKE and CAFFEINE

Answer 2

• Constituents in tobacco smoke induce CYP1A2 enzymes, which metabolize caffeine
• Caffeine levels increase ~56% upon quitting
• Nicotine withdrawal effects might be enhanced by increased caffeine levels
• Decrease caffeine intake by ~50% when quitting; no caffeine after 1PM for individuals with a typical bedtime

Question 3

PHARMACODYNAMIC DRUG

INTERACTIONS with SMOKING

Answer 3

Smokers who use combined hormonal contraceptives have an increased risk of serious cardiovascular adverse effects:

• Stroke
• Myocardial infarction
• Thromboembolism
• This interaction does not decrease the efficacy of hormonal contraceptives.