Does acyclovir side effects differ depending on dosage. i've been prescribed it before but on lower dosage and had no side effects.

Higher doses OK: Acyclovir (and valacyclovir, closely related) are among the safest of all drugs, with almost no toxicity or side effects. For occasional severe HSV and related infections (e.g. encephalitis, neonatal herpes) they are given is doses more than 10 times higher than the usual oral dose. If your doctor recommends a larger then of acyclovir than previously, you can safely follow that advice.

YEs: Common side effects from Acyclovir are abdominal pan, headache, lightheadedness, nausea and vomiting. As with most medications, the larger the dose the more likely the side effects.