Yes, it is safe to continue both Zyrtec (cetirizine) and Pepcid (famotidine) up to one week before your hysterectomy.
Both cetirizine and famotidine can be safely continued through the perioperative period for hysterectomy without increasing surgical risks or complications.
Rationale Based on Evidence
Why These Medications Are Safe to Continue
Neither cetirizine (an H1-antihistamine) nor famotidine (an H2-receptor antagonist) appear in any major perioperative medication management guidelines as requiring discontinuation before surgery 1, 2, 3, 2. This absence from restriction lists is clinically significant—medications that pose perioperative risks are explicitly addressed in these comprehensive guidelines.
Famotidine specifically has documented perioperative benefits:
- H2-receptor antagonists like famotidine are actually used intentionally in the perioperative setting to reduce gastric acidity and volume 4
- Studies show oral famotidine effectively reduces gastric volume and acidity during the perioperative period, which may reduce aspiration risk 4
- The FDA label for Pepcid lists no contraindications for surgical procedures 5
Cetirizine poses no identified perioperative concerns:
- The FDA label for Zyrtec contains standard warnings about drowsiness and sedation but no surgical contraindications 6
- Antihistamines are not mentioned in perioperative medication management guidelines as requiring discontinuation 1, 2, 3, 2
- The main consideration is potential additive sedation with anesthetic agents, which anesthesiologists routinely manage
What Medications Actually Need to Be Stopped
For context, medications that do require preoperative discontinuation include:
- Anticoagulants: Warfarin, DOACs (3-5 days before surgery) 1, 7, 1
- Antiplatelet agents: Clopidogrel (7 days), aspirin in high-bleeding-risk procedures (5 days) 1, 7, 1
- SGLT2 inhibitors: Stop the day before surgery due to ketoacidosis risk 8
- Certain muscle relaxants and analgesics: Specific guidance varies 2
Neither cetirizine nor famotidine fall into any high-risk medication category.
Practical Recommendations
Continue both medications as prescribed through the week before surgery, including:
- Take your regular doses up to and including the day before surgery
- Inform your anesthesiologist about these medications during your preoperative assessment
- The anesthesia team will account for potential sedative effects of cetirizine when dosing anesthetic agents
On the day of surgery:
- Follow your surgeon's and anesthesiologist's specific fasting instructions
- Generally, you may take essential medications with a small sip of water on the morning of surgery if instructed
- Confirm the morning-of-surgery medication plan during your preoperative visit
Important Caveats
- If you're taking cetirizine for chronic urticaria and have been on it long-term (>2 years), be aware that abrupt discontinuation can rarely cause rebound symptoms 9—another reason to continue it
- The combination of cetirizine and famotidine has been studied together and shown to be safe 10, 11
- Standard perioperative precautions apply: avoid alcohol, inform providers of all medications, and follow fasting guidelines 4
The bottom line: There is no evidence-based reason to stop either medication before your hysterectomy, and famotidine may actually provide protective benefits against aspiration.