Shingles is an infection caused by the varicella-zoster virus, which is the virus that causes chickenpox. Shingles occurs in people who have had chickenpox and represents a reactivation of the dormant varicella-zoster virus. The disease generally affects the elderly, although it occasionally occurs in younger and/or immunodeficient individuals. The first sign is usually a tingling feeling, itchiness, or stabbing pain on the skin. After a few days, a rash appears as a band or patch of raised dots on the side of the trunk or face. The rash develops into small, fluid-filled blisters which begin to dry out and crust over within several days. When the rash is at its peak, symptoms can range from mild itching to extreme and intense pain. Contact with a person with shingles may cause chickenpox (but not shingles) in someone who has never had chickenpox before.
Is there any treatment?
Treatment for shingles includes antiviral drugs, steroids, antidepressants, anticonvulsants, and topical agents. The severity and duration of an attack of shingles can be significantly reduced by immediate treatment with the antiviral drugs acyclovir, valacyclovir or famcyclovir. These drugs may also help stave off the painful aftereffects of shingles known as postherpetic neuralgia.
What is the prognosis?
Although shingles can be very painful and itchy, it is not generally dangerous to healthy individuals and it usually resolves without complications. The rash and pain usually go away within 3 to 5 weeks. Sometimes serious effects including partial facial paralysis (usually temporary), ear damage, or encephalitis (inflammation of the brain) may occur. Persons with shingles on the upper half of the face should seek medical attention immediately as the virus may cause serious damage to the eyes. Most people who have shingles have only one bout with the disease in their lifetime. However, individuals with impaired immune systems, i.e., people with AIDS or cancer, may suffer repeated episodes.
Generic name: Acyclovir
Why is this drug prescribed?
Zovirax liquid, capsules, and tablets, are used in the treatment of certain infections with herpes viruses. These include genital herpes, shingles, and chickenpox. This drug may not be appropriate for everyone, and its use should be thoroughly discussed with your doctor. Zovirax ointment is used to treat initial episodes of genital herpes and certain herpes simplex infections of the skin and mucous membranes.
Some doctors use Zovirax, along with other drugs, in the treatment of AIDS, and for unusual herpes infections such as those following kidney and bone marrow transplants.
Most important fact about this drug
Zovirax does not cure herpes. However, it does reduce pain and may help the sores caused by herpes to heal faster. Genital herpes is a sexually transmitted disease. To reduce the chance of infecting your partner, forgo intercourse and other sexual contact while you have sores or any other symptom.
How should you take this medication?
Your me dication should not be shared with others, and the prescribed dose should not be exceeded. Zovirax ointment should not be used in or near the eyes.
To reduce the risk of spreading the infection, use a rubber glove to apply the ointment.
You can take Zovirax with or without food.
--If you miss a dose...
Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time.
If you are using the ointment, apply it as soon as you remember and continue your regular schedule.
Store Zovirax at room temperature in a dry place.
What side effects may occur?
Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Zovirax.
More common side effects may include:
Diarrhea, general feeling of bodily discomfort, nausea, vomiting
Other reported side effects include:
Aggressive behavior, agitation, allergic reactions, blood in the urine, coma, confusion, decreased consciousness, delirium, dizziness, fever, hair loss, hallucinations, headache, hives, itching, kidney failure, lack of coordination, pain, psychosis, rash, seizures, skin peeling, sleepiness, swelling, swollen face and throat, swollen lymph nodes, tingling, upset stomach, vision problems, yellowish skin and eyes
Common side effects of Zovirax ointment may include:
If you are sensitive to or have ever had an allergic reaction to Zovirax or similar drugs, you should not take this medication. Make sure that your doctor is aware of any drug reactions that you have experienced.
Special warnings about this medication
If you are being treated for a kidney disorder, consult your doctor before taking Zovirax. The drug has been known to cause kidney failure.
If you develop unusual bruising or bleeding under the skin, be sure to alert your doctor. It could signal a dangerous blood disorder.
Possible food and drug interactions when taking this medication
If Zovirax is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Zovirax with the following:
Cyclosporine (Sandimmune, Neoral)
Special information if you are pregnant or breastfeeding
Zovirax seems relatively safe during pregnancy. Nevertheless, it should be used only if its benefits outweigh the potential risk to the baby. If you are pregnant or plan to become pregnant, inform your doctor immediately. Zovirax appears in breast milk and could affect a nursing infant. If this medication is essential to your health, your doctor may advise you to discontinue breastfeeding your baby until your treatment with Zovirax is finished.
For Genital Herpes
The usual dose is one 200-milligram capsule or 1 teaspoonful of liquid every 4 hours, 5 times daily for 10 days. If the herpes is recurrent, the usual adult dose is 400 milligrams (two 200-milligram capsules, one 400-milligram tablet or 2 teaspoonfuls) 2 times daily for up to 12 months.
If genital herpes is intermittent, the usual adult dose is one 200-milligram capsule or 1 teaspoon of liquid every 4 hours, 5 times a day for 5 days. Therapy should be started at the earliest sign or symptom.
Ointment: Apply ointment to affected area every 3 hours, 6 times per day, for 7 days. Use enough ointment (approximately one-half inch ribbon of ointment per 4 square inches of surface area) to cover the affected area.
For Herpes Zoster (Shingles)
The usual adult dose is 800 milligrams (one 800-milligram tablet or 4 teaspoonfuls of liquid) every 4 hours, 5 times daily for 7 to 10 days.
The usual adult dose is 800 milligrams 4 times a day for 5 days.
If you have a kidney disorder, the dose will need to be adjusted by your doctor.
The usual dose for chickenpox in children 2 years of age and older is 20 milligrams per 2.2 pounds of body weight taken orally 4 times daily, for a total of 80 milligrams per 2.2 pounds, for 5 days. A child weighing more than 88 pounds should take the adult dose.
The safety and effectiveness of oral Zovirax have not been established in children under 2 years of age. However, your doctor may decide that the benefits of this medication outweigh the potential risks. The safety and effectiveness of Zovirax ointment in children have not been established.
Your doctor will start you at the low end of the dosage range, since older adults are more apt to have kidney problems or other disease, or to be taking other medications.
Zovirax is generally safe. However, any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.
The FDA has approved an adjuvanted, recombinant varicella zoster virus (VZV) vaccine (Shingrix – GSK) for prevention of herpes zoster (shingles) in adults =50 years old. Shingrix is the second herpes zoster vaccine to be approved in the US; Zostavax, a live-attenuated VZV vaccine approved for the same indication, has been available since 2006.1,2
HERPES ZOSTER – Following primary infection, VZV persists in a latent form in sensory ganglia; VZV-specific cell-mediated immunity (CMI) prevents reactivation and multiplication of latent virus. When CMI falls below a critical threshold, as it can in older and immunocompromised persons, VZV can reactivate, causing shingles and, occasionally, postherpetic neuralgia (PHN) and other complications. About 1 million cases of shingles occur in the US each year.3,4
ZOSTAVAX – In clinical trials, the live-attenuated vaccine significantly reduced the incidence and severity of herpes zoster and PHN in adults =50 years old, but its effectiveness declines sharply with age (see Table 1), and its protection against shingles wanes to 4% within 8 years after inoculation in persons vaccinated at =60 years old.5-9 Zostavax is contraindicated for use in immunocompromised patients and it must be frozen during storage and transport. The Advisory Committee on Immunization Practices (ACIP) recommends Zostavax only for adults =60 years old, even though it was approved by the FDA for use in those =50 years old.10
SHINGRIX – The new recombinant vaccine contains a surface VZV glycoprotein E (gE) antigen obtained from cultured, genetically engineered Chinese hamster ovary cells that triggers a targeted immune response to VZV. It also contains a liposomal adjuvant (AS01B) to enhance the immune response. Unlike Zostavax, Shingrix is not contraindicated for use in immunocompromised patients and does not need to be frozen during storage and transport.
CLINICAL STUDIES – FDA approval of Shingrix was based on the results of two observer-blind trials, one in adults =50 years old and the other in adults =70 years old, in which a total of 27,922 persons were randomized to receive two doses of vaccine or placebo two months apart.11,12 The vaccine was effective in preventing herpes zoster and PHN in all age groups. Pooled results of the trials are summarized in Table 1.
The duration of protective immunity against shingles with Shingrix is unknown. In persons =70 years old, vaccine efficacy was 85.1% in the fourth year after vaccination.12 Immunogenicity data suggest that the protective effect of Shingrix will persist for at least 9 years after vaccination.13 The efficacy of Shingrix in persons who receive only one dose is not known. Shingrix and Zostavax have not been compared in head-to-head trials.
ADVERSE EFFECTS — Although not directly compared to one another in clinical trials, adverse reactions appear to occur more often with Shingrix than with Zostavax. Common adverse effects of the new vaccine include myalgia (45%), fatigue (45%), headache (38%), shivering (27%), fever (21%), GI symptoms (17%), and injection-site pain (78%), redness (38%), and swelling (26%). Severe local reactions preventing normal daily activities occurred in 17% of persons who received Shingrix and persisted for a mean of 2 days. Serious adverse events, including new-onset immune-mediated disease and death, occurred at similar rates in the vaccine and placebo groups. Long-term data on the safety of Shingrix are lacking.
DRUG INTERACTIONS – The efficacy of Shingrix may be reduced in patients who are receiving immunosuppressive therapy.
DOSAGE AND ADMINISTRATION – Shingrix should be given as two 0.5-mL doses administered intramuscularly 2-6 months apart. It can be given at the same time as influenza vaccine, but a different injection site should be used.
The vaccine is supplied in two single-dose vials, one containing the lyophilized antigen component and the other containing the adjuvant suspension component. Both vials should be refrigerated during storage; the vaccine should be discarded if frozen. Before administration, the antigen component must be reconstituted with the adjuvant component to form an opalescent, colorless to pale-brown liquid. The reconstituted vaccine should either be administered immediately or refrigerated and given within 6 hours. It should be discarded if it appears discolored or contains visible particulates.
NEW RECOMMENDATIONS – The ACIP now recommends that healthy adults =50 years old, including those who have already received Zostavax, be vaccinated with two doses of Shingrix (2-6 months apart).10 The committee voted that Shingrix is preferred over Zostavax for herpes zoster prevention. The optimal time between administration of Zostavax and revaccination with Shingrix has not been established.
CONCLUSION – The adjuvanted, recombinant varicella zoster virus (VZV) vaccine (Shingrix) appears to be considerably more effective than the live-attenuated VZV vaccine (Zostavax) for prevention of herpes zoster (shingles), especially in older patients. Two doses of Shingrix administered 2-6 months apart are now recommended for healthy adults =50 years old, including those who have previously received Zostavax. Ensuring completion of the two-dose series may be challenging, particularly in patients who experience severe adverse effects with the first dose.