Patients will ask if they should retake an oral med after vomiting.
Consider timing...especially if guidance isn’t in the labeling.
Generally suggest redosing if vomiting occurs within about 15 minutes of the dose...or if the intact drug is in the vomitus.
But redosing isn’t usually needed if the dose was over an hour ago.
Individualize the plan when vomiting occurs 15 to 60 min after a dose...it’s a gray area.
Lean toward redosing when the consequences of a missed dose outweigh the risk of getting an extra dose.
For example, advise redosing meds for hep C, HIV, and acute infections...especially single doses, such as doxycycline postexposure prophylaxis for STI prevention.
Be aware of specifics with oral contraceptives. Recommend redosing a progestin-only pill or emergency contraceptive if vomiting occurs within 3 hours of a dose. But combo OCs don’t usually need redosing after one episode of vomiting.
When redosing, consider checking to see if the culprit med can be taken with food...to limit GI upset. Or suggest an antiemetic (ondansetron, promethazine, etc) if needed.
If patients report vomiting frequently with a certain med, evaluate if changing the route of administration...or the med...is an option. For instance, change an oral triptan to an injectable or intranasal triptan.
Avoid redosing in most other cases, especially if an extra dose could be toxic...or a missed dose isn’t likely to change outcomes.
For example, explain that adverse effects are a concern with anticoagulants, methotrexate, or phenytoin...meds for ADHD, diabetes, or hypertension...or some long-acting meds, especially opioids.
And point out that it’s okay to miss a dose for meds with a delayed therapeutic impact (statins, bisphosphonates, dementia Rxs, etc)...or a long half-life (amiodarone, fluoxetine, etc).
In general, don’t redose sublingual or buccal meds...since these are absorbed through the oral mucosa.
Work with specialist prescribers for help with cancer meds, transplant immunosuppressants, etc. Extra monitoring may be needed.
Notify the prescriber before dispensing an extra dose...and document the approval to avoid charge-backs during a payer audit.
Keep our Redosing Oral Medications After Vomiting algorithm handy for step-by-step guidance.
- Thangaraju P, Natha JS, Venkatesan S, Tanguturi Yella SS. A Survey from a Tertiary Care Hospital in India on Pediatric Medication Re-Dosing Practices After Patient Vomiting. J Pediatr Pharmacol Ther. 2022;27(5):457-462.
- Kendrick JG, Ma K, Dezorzi P, Hamilton D. Vomiting of oral medications by pediatric patients: survey of medication redosing practices. Can J Hosp Pharm. 2012 May;65(3):196-201.
- Curtis KM, Nguyen AT, Tepper NK, et al. U.S. Selected Practice Recommendations for Contraceptive Use, 2024. MMWR Recomm Rep. 2024 Aug 8;73(3):1-77.
- Stillhart C, Vučićević K, Augustijns P, et al. Impact of gastrointestinal physiology on drug absorption in special populations--An UNGAP review. Eur J Pharm Sci. 2020 Apr 30;147:105280. doi: 10.1016/j.ejps.2020.105280.