Description

Aciclovir is an antiviral medication (nucleoside analogue) used for treating infections caused by herpes simplex virus—including cold sores, genital herpes—and varicella‑zoster virus (chickenpox, shingles). Both 200 mg and 400 mg oral tablets are available in the UK under prescription-only status.

 Prescription

Only available via prescription (POM) through a GP, clinic, or licensed online pharmacy in the UK. Tablets (200 mg, 400 mg, 800 mg) are not available over the counter .

Therapeutic Category

• Antiviral (herpesvirus treatment)
• Used for treatment and suppression of herpes simplex infections (cold sores, genital herpes), and treatment of shingles or chickenpox in certain cases.
  

Active Ingredients / Composition

• Aciclovir (acyclovir): Tablets contain either 200 mg or 400 mg of the active ingredient. No added vitamins or minerals.

 Vitamins

• None. 

 Minerals

• None. 

Variant

• 200 mg and 400 mg film-coated oral tablets, as well as 800 mg variants. UK brands include Accord‑UK (generic), Boots, GSK (Zovirax original), Aurobindo, Milpharm, Ranbaxy, Teva, Wockhardt, etc. Packaging is typically in blister packs of 6, 12, 15, 30, or 56 tablets depending on strength and intended use (treatment vs. suppression).

Consume Type

• Oral solid (film-coated tablet). Can be swallowed whole with water or dissolved in water—especially for those with swallowing difficulties.

 Directions / Usage

200 mg Tablets

• Cold sores & genital herpes (treatment): 200 mg five times daily (~every 4 hrs) for 5 days (omit middle-of-night dose).
• Suppression (recurrences): 200 mg four times daily (~every 6 hrs), or alternative regimens including 400 mg twice daily, as advised by physician .
  

400 mg Tablets

• Treatment of genital herpes: 400 mg three times daily for 5 days, or 800 mg three times daily for 2 days for short-course high-dose option .
• Suppression: 400 mg twice daily for 6 to 12 months; reassess after 12 months and consider breaks if appropriate .
  General guidance: Begin treatment at earliest onset of symptoms (e.g., tingling before cold sore appears) and maintain good hydration throughout course .

Common Side Effects

• Common : nausea, headache, diarrhea, skin rash, fatigue, dizziness, photosensitivity reactions (rash on sun‑exposed skin)
• Occasional/Infrequent  confusion, vertigo, abdominal pain, constipation, hair loss, edema, weakness.
  
• Rare : neurotoxicity (hallucinations, seizures), renal impairment (crystalluria), blood disorders (leukopenia, TTP), severe skin reactions (SJS/TEN), anaphylaxis .

Package Type

• Packaged in blister strips—commonly 6, 12, 15, or 30 tablets depending on strength and intended course. Larger packs (e.g. 56 tablets) may be used for suppressive regimens.

Storage Advice

• Store at room temperature (ideally 15‑25°C), protected from moisture and light.
• Keep in sealed blister until use; childproof storage recommended.
  

 Safety Advice

• Hydration is essential—drink plenty of fluids to support renal elimination and prevent crystalluria.
• Use with caution in renal impairment—dose adjustment required for reduced creatinine clearance (e.g., 200 mg twice daily if clearance <10 mL/min). 
• Photosensitivity: use sun protection.
• Pregnancy & breastfeeding: Aciclovir is generally considered safe, but consult your physician before use.
• Potential drug interactions: with probenecid, cimetidine, mycophenolate (immunosuppressant), and other nephrotoxic/renal excreted drugs—use caution and monitor renal function .

Product Substitutes

• Zovirax (brand name by GSK)
  Multiple generic manufacturers: Boots, Aurobindo, Actavis, Milpharm, Ranbaxy, Teva, Wockhardt, Accord‑UK, etc.—all provide equivalent aciclovir tablets in 200 mg, 400 mg, and 800 mg strengths. 
• Alternative antiviral agents: valaciclovir and famciclovir—longer-acting prodrugs of aciclovir with less frequent dosing and higher bioavailability, but more costly and regulated similarly as prescription-only .
  

Manufacturer / Marketer

• Accord‑UK Ltd holds the marketing authorization for Aciclovir Tablets BP 200 mg and 400 mg in the UK. Other companies (e.g. Boots, Aurobindo, Teva) also manufacture licensed generics in the UK market under MHRA approval.

Country of Origin

•  United Kingdom