Most people have no problems when taking acyclovir. Side effects, however, are possible. The most commonly reported ones include nausea, diarrhea, and a general ill feeling. In some cases, more serious side effects of acyclovir can occur. If you experience symptoms such as hallucinations, seizures, or signs of an allergic reaction, be sure to seek immediate medical attention.
An Introduction to Acyclovir Side Effects
As with any medicine, side effects are possible with
acyclovir (
Zovirax®); however, not everyone who takes the medication will experience side effects. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with acyclovir. Your healthcare provider can discuss a more complete list of acyclovir side effects with you.)
Common Acyclovir Side Effects
Acyclovir has been studied thoroughly in clinical trials, in which a group of people taking the drug have side effects documented and compared to another group not taking the medicine. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.
In these studies, the most common side effects of acyclovir included:
- A general ill feeling -- in up to 11.5 percent of people
- Nausea or vomiting -- up to 4.8 percent
- Diarrhea -- up to 2.7 percent
- Headaches -- up to 2.2 percent.
Serious Acyclovir Side Effects
Some side effects with acyclovir, while occurring infrequently, are potentially serious and should be reported immediately to your healthcare provider. These include but are not limited to:
- Aggressiveness or agitation
- Hallucinations
- Unusual bruising or bleeding
- Seizures
- Unusual decrease in urine production
- Signs of an allergic reaction, including unexplained rash, hives, itching, and unexplained swelling.