Oral contraceptives | All | About +40% |
Quinolone antibiotics | Ami- and difloxacin | +21% |
| Ciproflacin | +70% |
| Enoxacin | +75% |
| Fleroxacin | No effect |
| Grepafloxacin | +50% |
| Lomeflaxin | +23% |
| Nalidixic acid | +67% |
| Norfloxacin | +35% |
| Ofloxacin | No effect |
| Pefloxacin | +22–47% |
| Pipemidic acid | +59% |
| Rufloxacin | No effect |
| Temafloxacin | No effect |
| Tosufloxacin | +34% |
| Trovafloxacin | No effect |
Cardiovascular drugs | Mexiletine (anti-arrhythmic) | +30%–50% |
| Diltiazem (calcium antagonist) | +22% |
| Verapamil (calcium antagonist) | +20% |
| Propafenone (anti-arrhythmic) | Increase |
| Propranolol (beta-blocker) | Increase |
| Triamterene (diuretic) | Increase |
| Warfarin (anticoagulant) | Increase |
CNS drugs | Clozapine (antidepressant) | Variable, up to +26% |
| Fluvoxamine (antidepressant) | −80%; decreases caffeine half-life by sixfold |
| Venlafaxine (antidepressant, serotonin-norepinephrine reuptake inhibitor (SNRI) | No significant effect |
| Alprazolam (anti-anxiety) | No significant effect |
| Olanzapine (antipsychotic) (Shirley et al. 2003) | Slows clearance, interindividual variability |
| Tryptamine derivatives (psychoactive) | Slows caffeine clearance to various degrees |
| Armodafinil (wakefulness promoting) | No significant effect |
| Tacrine (cholinesterase inhibitor) | Slows slightly clearance |
| Zolpidem (Hypnotic) | No significant effect |
Anti-inflammatory drugs | Idrocilamide | Half-life increased up to 63 h |
| Rofecoxib | Decreased clearance |
Antifungal medication | Fluconazole | + 25% |
| Isavuconazole | No effect |
| Ketoconazole | + 11% |
| Terbinafine | + 21% |
Proton pump inhibitors | Cimetidine | −31% |
| Lansoprazole | No effect |
| Omeprazole | −41% |
| Pantoprazole | No effect |
| Ondansetron (anti-vomiting) | Slows clearance |
Psoralens, anti-psoriasis and anti-eczema drugs | Methoxsalen | −70% |
| 5-Methoxypsoralen | −31% |
Bronchodilators | Furafylline | Increases caffeine half-life up to 10-fold |
| Theophylline | Slows caffeine clearance, twofold |