Can You Take Buspar and Lithium Together?
Yes, you can take buspirone (Buspar) and lithium together by mouth—there are no significant drug interactions between these medications, and their combination is considered safe based on available evidence.
Evidence for Safety of This Combination
The combination of buspirone and lithium has been studied and used clinically without significant safety concerns:
A clinical study specifically evaluated the concomitant use of buspirone with lithium and found no significant adverse effects or drug interactions, supporting the safety of this combination 1.
Buspirone undergoes extensive hepatic metabolism primarily through oxidation, producing metabolites including 1-pyrimidinylpiperazine (1-PP), and does not significantly interact with medications that affect renal excretion like lithium 2, 3.
Lithium is eliminated primarily through renal excretion and does not undergo hepatic metabolism, meaning it does not interfere with the cytochrome P450 pathways that metabolize buspirone 2, 3.
Pharmacokinetic Compatibility
These medications have complementary elimination pathways that minimize interaction risk:
Buspirone has a short elimination half-life of approximately 2.5 hours and is metabolized hepatically with minimal renal involvement 2, 4.
Lithium is excreted unchanged by the kidneys and does not undergo hepatic metabolism, so it cannot interfere with buspirone's metabolic pathways 3.
Buspirone does not displace other highly protein-bound drugs and has minimal effects on hepatic enzyme systems, further reducing interaction potential 3.
Practical Considerations for Taking Both Medications
Timing of administration: You can take both medications at the same time or separately—there is no need to space them apart 1.
Food effects: Taking buspirone with food increases its bioavailability by approximately 2-fold, but this does not create safety concerns with lithium 2, 3.
Monitoring requirements: Continue your routine lithium monitoring (serum levels, renal function, thyroid function every 3-6 months) as prescribed, but no additional monitoring is required specifically for the combination 5.
Important Safety Considerations
While the combination is safe, maintain awareness of each medication's individual side effects:
For lithium: Monitor for signs of lithium toxicity (tremor, confusion, nausea, diarrhea), maintain adequate hydration and consistent salt intake, and attend scheduled laboratory monitoring 5.
For buspirone: Common side effects include headache, dizziness, nervousness, and lightheadedness, which are generally mild and do not interact with lithium 4.
Renal function: If you have kidney disease, buspirone clearance may be modestly decreased, but this does not create additional risk when combined with lithium 3.
Common Pitfalls to Avoid
Do not stop either medication abruptly without consulting your prescriber—lithium withdrawal is associated with dramatically increased relapse risk, especially within 6 months of discontinuation 5.
Maintain consistent dosing schedules for both medications to ensure stable therapeutic levels, particularly for lithium which requires steady-state concentrations 5.
Report any new symptoms to your healthcare provider, but understand that buspirone and lithium together do not create unique interaction-related adverse effects beyond what each medication can cause individually 1.