When it comes to herpes viruses, most healthcare professionals prescribe Acyclovir or Valacyclovir. These are prescription medications. Acyclovir and Valacyclovir are antiviral drugs that are used to treat herpes infections. Both are effective antiviral medications to treat infections caused by herpes virus including oral herpes, genital herpes, and shingles. These medicines do not cure herpes infections however significantly help ease symptoms, manage outbreaks, and diminish the frequency of outbreaks.
Are Acyclovir and Valcyclovir The Same?
Valacyclovir is the prodrug of Acyclovir. However, both are primarily similar there are some considerable differences between Acyclovir and Valacyclovir such as brand name affiliations, FDA-approved uses, dosing guidelines, and side effects, etc.
Chemically, Valcyclovir and Acyclovir are closely same however both are different drugs. During the first pass metabolism of the oral dosage, Valacyclovir is changed into Acyclovir which allows more active absorption of ingredients from the oral administration and also allows more time between multiple doses.
Valacyclovir and Acyclovir are antivirals that speed up the healing of blisters and sores and lessen pain in patients suffering from shingles, genital herpes, cold sores, and chickenpox. In this blog, we are throwing light on similarities, differences, and other in-depth comparisons of these drugs so stay here till the end.
What is Valacyclovir?
Valcyclovir is an oral dosage form that comes under the brand name Valtrex. Valacyclovir is FDA-approved for the treatment of shingles, cold sores, and genital herpes in adults. It is also used for the suppression of the virus in patients with compromised immune systems. In children and adolescents, Valacyclovir is FDA-approved for the treatment of cold sores and chickenpox.
Valacyclovir may also be prescribed when the herpes simplex virus causes blistering or sores in different areas of the body. It is an off-label use of this drug.
How Does It Work to Treat Herpes Simplex Virus?
Valacyclovir is the prodrug of Acyclovir. It means when you consume it, your liver somewhat changes the chemical structure of Valcyclovir and converts it into Acyclovir. It dominates the viruses by implanting itself into the growing DNA chain of the virus, discontinuing growth and reducing the ability of the virus to produce more copies of itself.
What is Acyclovir?
Acyclovir comes in different dosage forms including oral capsules, tablets, oral suspension, and topical creams and ointment. It also comes in the form of an injectable that should only be administered by a healthcare professional. Zovirax is a common brand name for Acyclovir that is available as cream or ointment. Sitavig is another that comes as buccal tablets.
FDA-approved adult uses of Acyclovir include the treatment of cold sores, shingles, and genital herpes including the lessening of the chances of transmission and treatment and suppression of virus in patients with compromised immune systems. FDA-approved uses of Acyclovir in children and adolescents include chickenpox and cold sores.
Off-label uses of Acyclovir include herpes simplex meningitis, viral encephalitis (inflammation or infection of the brain), and acute retinal necrosis.
How does it work against Herpes Infections?
Acyclovir works just like Valcyclovir after it is converted to the active form of this drug. It fixes itself in the DNA chain of the virus and stops further replication. It prevents the virus from making more copies of itself.
How Long Do These Medications Take to Work Against Genital Herpes, Cold Sores, And Other Herpes Infections?
Acyclovir and Valacyclovir help with cold sores within two to three days and improve the symptoms of genital herpes in around five days. The rashes and blisters may take a couple of weeks to disappear completely.
How long these medicines work against infection depends on how soon you begin with these drugs after the symptoms appear. If you start taking these medicines immediately after you notice the initial symptoms, you will have speedy recovery and better outcomes.
It is also extremely essential to take Acyclovir and Valcyclovir exactly as recommended by your doctor. Never miss or alter your doses without consulting your healthcare provider.
Comparative Efficiency
Both Acyclovir and Valacyclovir effectively speed up the healing of skin rashes and blisters, infection-associated pain, and other symptoms of shingles. Valacyclovir stays in your body for longer than Acyclovir so some patients can make it more reachable.
A study that featured more than 1000 adult patients demonstrated that Vlacyclovir resolves the symptoms of shingles faster than Acyclovir. Valacyclovir resolves the symptoms effectively in 38 days while Acyclovir in 51 days. Acyclovir and Valacyclovir both drugs work similarly, both are effective and generally not recommended over each other.
Is it Safe to Take Acyclovir and Valacyclovir Together?
It is not recommended to take Acyclovir and Valacyclovir together at the same time. Valacyclovir is transformed into Acyclovir inside your body so if you take both of these medicines at the same time you have too much Acyclovir in your body.
Taking Acyclovir and Valacyclovir together can increase your chances of serious side effects such as kidney damage. It is suggested to take one of these drugs at a time and not take both of these antivirals together. Always take these medicines precisely as prescribed by your doctor.
Side Effects
The side effects of these drugs are rare. Mostly the common side effects of both Acyclovir and Valcyclovir are mild and resolve independently without requiring any medical support. However, the most common side effects reported by patients while taking Valcyclovir and Acyclovir are nausea, diarrhea, vomiting, and headache.
Precautions
Serious side effects of Acyclovir and Valacyclovir are possible in certain circumstances such as if you are suffering from a kidney disease, in this case, you may require a lower dose than the normal dose to prevent further kidney damage.
Neurological issues such as confusion, hallucinations, and agitation are more common in older age people taking antiviral drugs such as Valacyclovir and Acyclovir.
People having a weakened immune system because of an advanced human immunodeficiency virus or transplant recipient patients may be at greater risk of developing hemolytic uremic syndrome that diminishes kidney function and thrombotic thrombocytopenic purpura, a blood clotting disorder that can cause damage to kidneys.
Acyclovir and Valacyclovir Associated Drug Interactions
Certain drugs should not be used together as it can cause an interaction or increase the chances of side effects. Acyclovir and Valacyclovir have not shown any significant interactions with common medications.
However, sharing the information about your current medications with your healthcare provider is still essential to be aware of potential problems. For instance, medications that are associated with kidney damage can put you at risk of kidney problems when taken with Acyclovir and Valacyclovir.
Valacyclovir and Acyclovir may have negative effects on the liver and kidneys in certain circumstances. That is why taking these drugs with other drugs that are hepatotoxic or nephrotoxic can be dangerous. Some drugs may interact with these drugs including other medicines that can cause kidney issues such as nonsteroidal anti-inflammatory drugs (Naproxen and Ibuprofen).
The concurrent use of certain drugs (eg. Cidofovir) with Acyclovir and Valacyclovir is contraindicated because of severe risk. The medicines that are strongly dejected from being used along with Acyclovir and Valacyclovir include Mannitol, Foscarnet, and Capreomycin.
Other medications that should not be used along with Acyclovir and Valacyclovir include Teriflunomide, Tenofovir Alafenamide, Nitisinone, Leflunomide, Foscarnet, Fexinidazole, Emtricitabine, Dichlorphenamide, Theophylline, Mycophenolate, Capreomycin. In case you need to take both medications at a time your doctor may modify the dose to avoid the risks.
Acyclovir or Valacyclovir Which is More Effective?
Acyclovir and Valacyclovir both are successful treatments for viral infections caused by herpes virus and varicella-zoster virus strains. Clinically, the most significant difference between these two medicines has been noticed during shingles treatment, as Valacyclovir leads to a shorter duration of pain and rarer complications.
You can not say that Valacyclovir is stronger than Acyclovir however it gets absorbed in your body more efficiently than Acyclovir. It means it has better oral bioavailability and more Valacyclovir makes it into your system.
A significant consideration while opting between Acyclovir and Valacyclovir is that Valacyclovir is dosed fewer times a day than Acyclovir reduces the pill burden for patients and is easier to manage and stays amenable to treatment regimens.
A randomized international double-blind trial was conducted to compare Acyclovir and Valacyclovir in the treatment of first episodes of genital herpes. Oral Acyclovir was given 5 times a day and Valacyclovir twice a day. Clinically no significant difference has been noticed in the lesion healing time, extent of pain, and duration to clear all symptoms.
Valacyclovir offers the advantage of fewer doses a day as compared to Acyclocir. It reduces the pill burden and the likelihood that patients will complete the prescribed course. Your doctor will recommend which is the best treatment for genital herpes infection.
Another randomized trial was conducted to compare Acyclovir and Valacyclovir oral tablets for the treatment of herpes zoster infection (shingles). The results demonstrated that Valacyclovir pointedly enhanced the pain resolution associated with shingles rash and the rash also resolved at similar times with fewer ocular complications.
Another considerable Advantage of Valacyclovir observed in this trial is that it just requires 3 doses a day as compared to 5 doses a day for Acyclovir. Eventually, only your doctor can determine the best treatment option for your herpes zoster infection.
Acyclovir and Valacyclovir During Pregnancy
Valacyclovir and Acyclovir pregnancy registries have tracked results for fetuses exposed to these medications in utero. No drug-related risk of major birth defects has been noticed in pregnant women.
There is no sufficient data to confirm miscarriages. However, there are known risks to HSV infections in the fetus during childbirth if the herpes virus infection is left untreated. Primary herpes virus infections during the first trimester of pregnancy can lead to neonatal skin lesions, chorioretinitis, and microcephaly.
Acyclovir and Valacyclovir With Alcohol
Although there is no contraindication to consuming alcohol while taking Acyclovir or Valacyclovir, patients should be cautious. Alcohol is processed by the liver and these antivirals may have negative effects on the liver. Make sure you talk to your healthcare professional and consult about it to prevent any adverse events.
Closing Words
Valacyclovir and Acyclovir both antivirals are effective drugs that significantly ease the symptoms, and associated pain and speed up the healing while suffering from genital herpes, recurrent genital herpes, oral cold sore lesions, and shingles.
It may be easy to take Valacyclovir because of its uncomplicated dosing schedule and it also improved shingles symptoms better than Acyclovir as per a study. Always remember that Acyclovir and Valacyclovir work best when you start taking them as you notice the first signs of symptoms including itching, tingling, or burning.
Taking Acyclovir and Valacyclovir at the same time can be dangerous so it is not recommended. At one time you should only use only one of them. Your healthcare professional will consider the important factors and your preferences to pick the best treatment for you.
