Jojo asked
I was prescribed a Zpack for pneumonia. I threw up within minutes of the first dose....later that day I took the second pill. Then I mixed up the order..today should be day 3...is this ok?
At a glance
- The time-frame for which Zithromax (azithromycin) needs to be re-dosed after vomiting depends on the dosage form (e.g. immediate-release or extended-release). For the tablets from the ZPak, it should re-dosed if you vomit within 5 minutes of taking and most likely should be re-dosed if your vomit within 30 minutes of taking.
Answer
Vomiting after taking a dose of medication can be extremely concerning, and it can be challenging to know whether or not it was adequately absorbed or not.
The natural question is whether or not you should retake your last dose of medication and unfortunately, the answer isn't always clear for the vast majority of drugs.
It goes without saying if you vomit immediately after taking a dose or you see an intact medication (such as a tablet) in your vomit (known as vomitus), it would be a good idea to re-dose as you clearly haven't absorbed the medication.
When it gets to be more than a few minutes after taking a dose that you vomit, it is important to evaluate the risk of treatment failure (from a dose that is not properly absorbed due to vomiting) versus the risk of side effects.
For example, it may make more sense to consider re-dosing an anti-infective medication (like Zithromax) or emergency contraceptive pill over a longer time-frame versus a maintenance medication like one for cholesterol.
On the other hand, it may be extremely risky to re-dose certain medications with potentially severe adverse effects, like strong opioids (oxycodone).
As you are concerned with Zithromax, I will cover that.
Zithromax After Vomiting
Fortunately for Zithromax (azithromycin), the prescribing information for the drug gives specific directions in a case where you throw up soon after taking a dose.
In fact, since Zithromax comes in various dosage forms (e.g., tablets, extended-release suspension), we have a few different recommendations.
Zithromax Extended-Release Suspension
The prescribing information for the extended-release suspension (ZMax) states the following:
"In the event that a patient vomits within 5 minutes of administration, the health care provider should consider additional antibiotic treatment since there would be minimal absorption of azithromycin. Since insufficient data exist on absorption of azithromycin if a patient vomits between 5 and 60 minutes following administration, alternative therapy should be considered. Neither a second dose of Zmax nor alternative treatment is warranted if vomiting occurs ≥60 minutes following administration, in patients with normal gastric emptying."
So, although there isn't a specific recommendation regarding whether or not to re-dose if you vomit after taking the extended-release Zithromax, it does give guidance:
- If you vomit within 5 minutes of taking a dose, retake it since absorption isn't likely to have occurred yet.
- If you vomit between 5 and 60 minutes following a dose, you should probably retake it since 'alternative therapy' should be considered.
- If you vomit more than 60 minutes after taking a dose, there is no need to retake a dose as long as you have normal GI function.
Zithromax Immediate-Release
Immediate-release Zithromax (azithromycin) products include:
- Film-coated tablets
- Suspension (non-extended release)
There is slightly less guidance available when it comes to these immediate-release versions of Zithromax. The prescribing information for these products states:
References
- Elsevier ClinicalKey: Zithromax (subscription required) (Accessed 1/29/19)
- Zmax Prescribing Information (Accessed 1/29/19)
- Zithromax Prescribing Information (Accessed 1/28/19)
- Vomiting of Oral Medications by Pediatric Patients: Survey of Medication Redosing Practices. PubMed (Accessed 1/29/19)
- Redosing of selected medications after vomiting. Prescriber's Letter (subscription required) (Accessed 1/29/19)
