Table 1.

Drugs or groups of drugs that are marked with at least ten bullet points in the drug interactions appendix in the British National Formulary (BNF 46)

Number of bullets	Drugs or groups of drugs
10–14	Amiodarone; antihistamines; barbiturates; beta-blockers; disopyramide; diuretics; oral contraceptives; indinavir; NSAIDs; quinidine; quinolone antibiotics; saquinavir; SSRIs; St John's wort; telithromycin
15–19	Antipsychotic drugs; calcium channel blockers; carbamazepine; erythromycin and other macrolides; monoamine oxidase inhibitors; nelfinavir; phenytoin; rifamycins; tricyclic antidepressants
20–24	Antifungal imidazoles and triazoles; ritonavir
25–29	Ciclosporin; warfarin