Is it okay to take Zyrtec and Zantac at the same time?
At a glance
- Zyrtec (cetirizine) is an H1-blocker while Zantac (ranitidine) is a H2-blocker. They can safely be taken together.
Zyrtec (cetirizine) and Zantac (ranitidine) are safe to take together. There is no drug interaction between them.
It can be a little confusing since both Zyrtec and Zantac are technically antihistamines. However, they work on different histamine receptors.
Zyrtec is an H1-antagonist. The binding of histamine to H1-receptors can produce many of the symptoms we associate with allergies, including:
- Runny nose
- Watery eyes
- Redness (erythema)
H1-antagonists, like Zyrtec bind to H1-receptor sites, blocking histamine from binding to them, preventing the above allergy symptoms.
It is important to note that antihistamines like Zyrtec do not block the release of histamine from mast cells. This is why antihistamines tend to work better if taken prior to being exposed to potential allergens.
Zantac, although not commonly called an 'antihistamine', is technically one, although it blocks a different histamine receptor (H2-receptors).
H2-receptors are located on parietal cells. Blocking them decreases basal and nocturnal gastric acid secretion as well as acid secretion in response to stimuli (e.g. food).
H2-blockers are used for the treatment of a variety of indications, including:
- Heartburn (pyrosis)
- Peptic ulcer disease
- GERD (gastroesophageal reflux disease)
There are several H2 blockers available on the market, and studies suggest all have similar efficacy. Choice of any specific one is generally determined on potential drug interactions and individual response.
An interesting note is that several studies have shown that H2-blockers can potentiate the effects of H1-blockers if used together. So not only are H1 and H2-blockers safe to use with each other, taking both can have greater efficacy than either alone.
- ClinicalKey: Ranitidine Monograph. ClinicalKey
- ClinicalKey: Cetirizine Monograph. ClinicalKey
- Pharmacological and pharmacodynamic essentials of H(2)-receptor antagonists and proton pump inhibitors for the practising physician. PubMed
- Histamine 2 blocker potentiates the effects of histamine 1 blocker in suppressing histamine-induced wheal. PubMed