Acyclovir in its tablet, injectable, and capsule forms is a prescription medication used for treating infections caused by the herpes viruses and varicella zoster. These infections include genital herpes, cold sores, and chickenpox. Both the oral and injectable forms of the medication are effective for treating these conditions, while the topical form is useful for treating genital herpes and certain herpes simplex virus infections in immunocompromised patients. Additionally, Acyclovir cream is prescribed for treating herpes labialis in children aged 12 years and older. However, your healthcare provider might also prescribe Acyclovir for conditions not listed in this document.



Side Effects of Acyclovir
The most common side effects associated with Acyclovir include headaches, nausea, vomiting, and diarrhea. If any of these symptoms persist or cause significant discomfort, it is important to notify your healthcare provider as soon as possible.



Your healthcare provider has prescribed Acyclovir because they have determined that its benefits outweigh the potential risks. According to clinical trials, most individuals using this medication—whether in injectable, capsule, tablet, or oral suspension form—do not experience serious side effects. However, some people may experience more serious side effects, though these are less common. These include:

Mental changes
Unsteady movement
Trembling
Difficulty speaking
Dizziness
Additionally, some individuals may develop signs of renal insufficiency, such as unusual back pain, changes in urine output, or side pain.

In very rare cases, a life-threatening reaction can occur that affects the kidneys, blood cells, and other critical organs. These reactions are more likely to occur in patients with weakened immune systems, such as those with HIV, kidney transplants, or bone marrow transplants. These patients should seek immediate medical assistance if they experience any of the following severe side effects:



Bleeding
High fever
Yellowing of the skin or eyes
Dark urine
Irregular heartbeat
Extreme fatigue
Vision changes
Loss of consciousness
Seizures
Bloody urine
Bruising
Rapid heartbeat
Severe stomach pain
Although very rare, severe allergic reactions can also occur with Acyclovir. If any of the following symptoms of an allergic reaction are observed, immediate medical attention is necessary:

Swelling of the face, throat, or tongue
Difficulty breathing
Severe dizziness
Rash
Itching

This is not an exhaustive list of side effects that may be associated with Acyclovir. If you experience side effects not listed here while using this antiviral medication, please inform your healthcare provider about the issues you are experiencing.