Acyclovir may be given orally or intravenously. Major drawbacks of orally administered acyclovir include its lower bioavailability compared with other agents and its dosing frequency five times daily. Intravenously administered acyclovir is generally used only in patients who are severely immunocompromised or who are unable to take medications orally. Valacyclovir, a prodrug of acyclovir, is administered three times daily.
Compared with acyclovir, valacyclovir may be slightly better at decreasing the severity of pain associated with herpes zoster, as well as the duration of postherpetic neuralgia. Famciclovir is also a DNA polymerase inhibitor. The advantages of famciclovir are its dosing schedule three times daily , its longer intracellular half-life compared with acyclovir and its better bioavailability compared with acyclovir and valacyclovir. The choice of which antiviral agent to use is individualized.
Dosing schedule and cost may be considerations. The recommended dosages for acyclovir, famciclovir and valacyclovir are provided in Table 1. All three antiviral agents are generally well tolerated. The most common adverse effects are nausea, headache, vomiting, dizziness and abdominal pain. Montvale, N. Cost to the patient will be higher, depending on prescription filling fee.
Antiviral agents are not used in combination, and selection of an agent is based on dosage schedule and cost. Orally administered corticosteroids are commonly used in the treatment of herpes zoster, even though clinical trials have shown variable results. Prednisone used in conjunction with acyclovir has been shown to reduce the pain associated with herpes zoster. Some studies designed to evaluate the effectiveness of prednisone therapy in preventing postherpetic neuralgia have shown decreased pain at three and 12 months.
If the use of orally administered prednisone is not contraindicated, adjunctive treatment with this agent is justified on the basis of its effects in reducing pain, despite questionable evidence for its benefits in decreasing the incidence of postherpetic neuralgia. Given the theoretic risk of immunosuppression with corticosteroids, some investigators believe that these agents should be used only in patients more than 50 years of age because they are at greater risk of developing postherpetic neuralgia.
The pain associated with herpes zoster ranges from mild to excruciating. Patients with mild to moderate pain may respond to over-the-counter analgesics. Patients with more severe pain may require the addition of a narcotic medication. Lotions containing calamine e. Once the lesions have crusted over, capsaicin cream Zostrix may be applied.
Topically administered lidocaine Xylocaine and nerve blocks have also been reported to be effective in reducing pain. Ocular herpes zoster is treated with orally administered antiviral agents and corticosteroids, the same as involvement elsewhere. Although most patients with ocular herpes zoster improve without lasting sequelae, some may develop severe complications, including loss of vision.
When herpes zoster involves the eyes, ophthalmologic consultation is usually recommended. The morbidity and mortality of herpes zoster could be reduced if a safe and effective preventive treatment were available. It is unusual for a patient to develop herpes zoster more than once, suggesting that the first reactivation of varicella-zoster virus usually provides future immunologic protection.
Studies are currently being conducted to evaluate the efficacy of the varicella-zoster vaccine in preventing or modifying herpes zoster in the elderly. Although postherpetic neuralgia is generally a self-limited condition, it can last indefinitely. Treatment is directed at pain control while waiting for the condition to resolve. Pain therapy may include multiple interventions, such as topical medications, over-the-counter analgesics, tricyclic antidepressants, anticonvulsants and a number of nonmedical modalities.
Occasionally, narcotics may be required. Dosage recommendations are provided in Table 2. Drug levels for clinical use are not available. Capsaicin, an extract from hot chili peppers, is currently the only drug labeled by the U. Food and Drug Administration for the treatment of postherpetic neuralgia. Substance P, a neuropeptide released from pain fibers in response to trauma, is also released when capsaicin is applied to the skin, producing a burning sensation.
Analgesia occurs when substance P is depleted from the nerve fibers. To achieve this response, capsaicin cream must be applied to the affected area three to five times daily. Patients must be counseled about the need to apply capsaicin regularly for continued benefit. They also need to be counseled that their pain will likely increase during the first few days to a week after capsaicin therapy is initiated. Patients should wash their hands thoroughly after applying capsaicin cream in order to prevent inadvertent contact with other areas.
Patches containing lidocaine have also been used to treat postherpetic neuralgia. One study found that compared with no treatment, lidocaine patches reduced pain intensity, with minimal systemic absorption. Although lidocaine was efficacious in relieving pain, the effect was temporary, lasting only four to 12 hours with each application.
Over-the-counter analgesics such as acetaminophen e. However, these agents are often useful for potentiating the pain-relieving effects of narcotics in patients with severe pain. Because of the addictive properties of narcotics, their chronic use is discouraged except in the rare patient who does not adequately respond to other modalities.
Tricyclic antidepressants can be effective adjuncts in reducing the neuropathic pain of postherpetic neuralgia. These agents most likely lessen pain by inhibiting the reuptake of serotonin and norepinephrine neurotransmitters. Tricyclic antidepressants commonly used in the treatment of postherpetic neuralgia include amitriptyline Elavil , nortriptyline Pamelor , imipramine Tofranil and desipramine Norpramin.
These drugs are best tolerated when they are started in a low dosage and given at bedtime. The dosage is increased every two to four weeks to achieve an effective dose. The tricyclic antidepressants share common side effects, such as sedation, dry mouth, postural hypotension, blurred vision and urinary retention.
Nortriptyline and amitriptyline appear to have equal efficacy; however, nortriptyline tends to produce fewer anticholinergic effects and is therefore better tolerated.
Treatment with tricyclic antidepressants can occasionally lead to cardiac conduction abnormalities or liver toxicity. The potential for these problems should be considered in elderly patients and patients with cardiac or liver disease.
Because tricyclic antidepressants do not act quickly, a clinical trial of at least three months is required to judge a patient's response. The onset of pain relief using tricyclic antidepressants may be enhanced by beginning treatment early in the course of herpes zoster infection in conjunction with antiviral medications.
Phenytoin Dilantin , carbamazepine Tegretol and gabapentin Neurontin are often used to control neuropathic pain. A recent double-blind, placebo-controlled study showed gabapentin to be effective in treating the pain of postherpetic neuralgia, as well as the often associated sleep disturbance. The anticonvulsants appear to be equally effective, and drug selection often involves trial and error.
Lack of response to one of these medications does not necessarily portend a poor response to another. The dosages required for analgesia are often lower than those used in the treatment of epilepsy. Anticonvulsants are associated with a variety of side effects, including sedation, memory disturbances, electrolyte abnormalities, liver toxicity and thrombocytopenia.
Side effects may be reduced or eliminated by initiating treatment in a low dosage, which can then be slowly titrated upward. There are no specific contraindications to using anticonvulsants in combination with antidepressants or analgesics. However, the risk of side effects increases when multiple medications are used. Effective treatment of postherpetic neuralgia often requires multiple treatment approaches. In addition to medications, modalities to consider include transcutaneous electric nerve stimulation TENS , biofeedback and nerve blocks.
Herpes zoster and postherpetic neuralgia are relatively common conditions, primarily in elderly and immunocompromised patients. Although the diagnosis of the conditions is generally straightforward, treatment can be frustrating for the patient and physician.
Approaches to management include treatment of the herpes zoster infection and associated pain, prevention of postherpetic neuralgia, and control of the neuropathic pain until the condition resolves. Primary treatment modalities include antiviral agents, corticosteroids, tricyclic antidepressants and anticonvulsants. Already a member or subscriber? Log in. Interested in AAFP membership? Learn more. When this happens, you can experience an outbreak of shingles.
Shingles outbreaks tend to be limited to a small area of your body, such as the chest or torso. Most people only notice shingles symptoms on one side of their body.
Shingles is a painful, unpleasant condition that can result in a burning sensation on the affected skin, as well as a painful red rash and fluid-filled sores. Sometimes, shingles only produces internal pain but no skin rash, leading many people to mistake it for other health issues. Luckily, shingles treatment is simple and can be remedied with medications like Valacyclovir. Your doctor will be able to provide advice and assistance to help you treat and recover from the shingles infection.
Luckily, valacyclovir starts working on the virus almost immediately to help your body fight it off quickly. However, keep in mind that like other forms of herpes, it's important to seek treatment as soon as possible. The earlier you start attacking it, the better. People above 60 and older should also consider a zoster vaccine, which can reduce the risk of shingles infection.
Finally, you should act as quickly as possible if you have any condition that could weaken your immune system, such as a chronic illness.
People with compromised immune systems have a greater risk of developing disseminated shingles, a potentially lethal form of shingles rash that can damage the skin, liver, brain and other organs. Shingles symptoms typically begin with itching, tingling, or burning in an area on one side of the body. One or two days later, a painful, burning rash made up of small fluid-filled blisters like chickenpox develops in that area. Herpes zoster usually only affects the area fed by a specific nerve whichever nerve is hiding the virus , and this area is called a dermatome.
New blisters will keep popping up in the next three to five days before crusting and eventually healing over the following two to four weeks. Other symptoms can include fever, headache, chills, and upset stomach.
This is called post-herpetic neuralgia, and it is the most common complication from herpes zoster Albrecht, Valacyclovir brand name Valtrex is an antiviral drug that works against herpes infections like genital herpes herpes simplex virus 2 , cold sores herpes simplex virus 1 , chickenpox VZV , and shingles VZV.
Antivirals work by making it harder for viruses to copy themselves and spread from cell to cell Ormrod, Valacyclovir is a prescription drug that you take by mouth as soon as possible after developing the virus. It is important to know that valacyclovir does not cure the virus forever—it only treats the current episode, making it less painful and resolve faster than it would without medication.
Also, valacyclovir can be used long term suppressive therapy to prevent or suppress outbreaks. Valacyclovir is an FDA-approved treatment for herpes zoster as well as genital herpes and cold sores. It decreases the duration and severity of symptoms FDA, It should be started as soon as possible after the rash starts. You will get the best response if you take the medication within 72 hours of the rash appearing Ormrod, Sometimes, depending on your pain level, your healthcare provider may recommend pain medication or over-the-counter remedies calamine lotion, oatmeal baths, etc.
As with other herpes viruses, valacyclovir does not cure shingles—it can make your current episode less painful and resolve faster if started right away.
Valacyclovir is generally well tolerated. However, like all drugs, valacyclovir does have side effects. The most common side effects of valacyclovir include headache, nausea, abdominal pain, tiredness, depression, and skin rash UpToDate, n. Let your healthcare provider know if you experience any of these symptoms, especially if they are severe or do not improve. Serious side effects can occur, especially in the elderly, people with kidney problems, or those with weakened immune systems.
Elderly people who use this medication are at a higher risk of central nervous system side effects like agitation, hallucinations, confusion, etc.
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