What is the most important information I should know about acyclovir?

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated.

Treatment with acyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Herpes infections are contagious and you can infect other people, even while you are being treated with acyclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

What should I discuss with my healthcare provider before taking acyclovir?

Do not take this medicine if you are allergic to acyclovir or valacyclovir (Valtrex). Before taking acyclovir, tell your doctor if you are allergic to any drugs, or if you have kidney disease. You may need a dosage adjustment or special tests during treatment. FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Herpes virus can be passed from an infected mother to her baby during childbirth. If you have genital herpes, it is very important to prevent herpes lesions during your pregnancy so that you do not have a genital lesion when your baby is born. Acyclovir passes into breast milk and may harm a nursing infant. Do not take this medication without telling your doctor if you are breast-feeding a baby.

How should I take acyclovir?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Treatment with acyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Take each dose with a full glass of water. Drink plenty of water while you are taking acyclovir to keep your kidneys working properly.

Acyclovir can be taken with or without food. Taking acyclovir with food may decrease stomach upset.

Shake the oral suspension (liquid) well just before you measure a dose. To be sure you get the correct dose, measure the liquid with a marked measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one. Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Acyclovir will not treat a viral infection such as the common cold or flu.

Lesions caused by herpes viruses should be kept as clean and dry as possible. Wearing loose clothing may help to prevent irritation of the lesions.

Store acyclovir at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include seizure (convulsions), hallucinations, and urinating less than usual or not at all.

What should I avoid while taking acyclovir?

Herpes infections are contagious and you can infect other people, even while you are being treated with acyclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

Acyclovir will not prevent the spread of genital herpes. Avoid sexual intercourse or use a latex condom to prevent spreading the virus to others.

Acyclovir side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have any of these serious side effects:

• pain in your lower back;
• urinating less than usual or not at all;
• easy bruising or bleeding; or
• unusual weakness.

Less serious side effects may include:

• nausea, vomiting, diarrhea, loss of appetite, stomach pain;
• headache, feeling light-headed; or
• swelling in your hands or feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.