Famciclovir tablets, 500 mg, packaged in 30-count unit dose cartons, Rx only, Manufactured for: ...

Nitrosamines are probable human carcinogens — they can increase cancer risk with long-term exposure above certain thresholds, but they do not cause immediate harm from taking a single dose. The FDA calculates an acceptable daily intake (ADI) for each nitrosamine compound, and recalls are triggered when levels exceed this threshold. If you have been taking a recalled product, the FDA generally advises against abruptly stopping your medication (especially for critical conditions like blood pressure or diabetes) until you consult your doctor. The incremental cancer risk from short-term exposure is very small.

Not necessarily. Many drug recalls are initiated because of quality system failures or test results that suggest a product might not meet specifications — even if no patients have reported harm. The FDA uses a precautionary approach: if there is reason to believe quality standards were not met, a recall is required regardless of whether adverse effects have been reported. Class I recalls typically involve a reasonable probability of harm; Class II recalls may cause temporary health issues; Class III recalls are for products unlikely to cause adverse health consequences but that still violate regulations.

Pharmacies typically receive recall notices directly from drug wholesalers and manufacturers within days of the recall being announced. Your pharmacist can look up whether any product in your prescription history matches a recalled lot number. For current recalls, the FDA publishes updates at FDA.gov/safety/recalls-market-withdrawals-safety-alerts and sends MedWatch email alerts for significant drug safety issues. You can sign up for MedWatch alerts at FDA.gov. Most major pharmacy chains also have their own recall notification systems that automatically alert pharmacists when a recalled product is in their inventory.