Concentrations and effects of buspirone are considerably reduced by rifampicin.

Article Details

Citation

Lamberg TS, Kivisto KT, Neuvonen PJ

Concentrations and effects of buspirone are considerably reduced by rifampicin.

Br J Clin Pharmacol. 1998 Apr;45(4):381-5. doi: 10.1046/j.1365-2125.1998.t01-1-00698.x.

PubMed ID
9578186 [ View in PubMed
]
Abstract

AIMS: The effects of rifampicin on the pharmacokinetics and pharmacodynamics of buspirone, a non-benzodiazepine anxiolytic agent, were investigated. METHODS: In a randomized, placebo-controlled cross-over study with two phases, 10 young healthy volunteers took either 600 mg rifampicin or matched placebo once daily for 5 days. On day 6, 30 mg buspirone was administered orally. Plasma buspirone concentrations and effects of buspirone were measured up to 10 h. RESULTS: The total area under the plasma buspirone concentration-time curve after rifampicin was 10.4% (95% CI, 6.3-14.5%) of that after placebo (1.64+/-0.35 ng ml(-1) h vs 22.0+/-15.1 ng ml(-1) h (mean+/-s.d.); P< 0.01). Rifampicin decreased the peak plasma concentration of buspirone from 6.6+/-3.7 ng ml(-1) to 0.84+/-0.23 ng ml(-1) (P< 0.01) and the half-life from 2.8+/-0.7 h to 1.3+/-0.5 h (P< 0.01). A significant (P<0.05) reduction in the effects of buspirone was observed in three of the six psychomotor tests employed (postural sway test with eyes closed, subjective drowsiness and overall drug effect) after rifampicin pretreatment. CONCLUSIONS: The strong interaction between rifampicin and buspirone is probably mostly due to enhanced CYP3A4-mediated first-pass metabolism of buspirone. Buspirone will most likely show a greatly reduced anxiolytic effect when used together with rifampicin or other potent inducers of CYP3A4 such as phenytoin and carbamazepine.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
BuspironeCytochrome P450 3A4ProteinHumans
Unknown
Substrate
Details
Drug Interactions
DrugsInteraction
Buspirone
Erythromycin
The serum concentration of Buspirone can be increased when it is combined with Erythromycin.
Buspirone
Itraconazole
The serum concentration of Buspirone can be increased when it is combined with Itraconazole.
Buspirone
Rifampicin
The serum concentration of Buspirone can be decreased when it is combined with Rifampicin.