Basic
Informations
Viramune is an HIV medication.
It is in a category of HIV medicines called non-nucleoside reverse
transcriptase inhibitors (NNRTIs). Viramune prevents HIV from
entering the nucleus of healthy CD4 cells. This prevents the cells
from producing new virus and decreases the amount of virus in the
body.
Viramune, manufactured by Boehringer-Ingelheim, was approved by the
U.S. Food and Drug Administration for the treatment of HIV in 1996.
Viramune is available in standard immediate-release tablets, which
is taken twice-daily, and in an extended-release formation called
Viramune XR, which is taken once-daily.
Viramune must be used in combination with other drugs to treat HIV.
It is usually combined with two nucleoside analogues.
Drugs
Interactions
Viramune is broken down
(metabolized) by the liver, like many medications used to treat HIV
and AIDS. This means that Viramune can interact with other
medications. Viramune can lower or raise the levels of other
medications in the body. Similarly, other medications can lower or
raise the levels of Viramune in the body. While many interactions
are not a problem, some can cause your medications to be less
effective or increase the risk of side effects.
Tell your doctors and pharmacists about all medicines you take. This
includes those you buy over-the-counter and herbal or natural
remedies, such as St. John’s Wort. Bring all your medicines when you
see a doctor, or make a list of their names, how much you take, and
how often you take them. Your doctor can then tell you if you need
to change the dosages of any of your medications.
The following medications
should not be taken while you are being treated with Viramune
All of the available
nucleoside reverse transcriptase inhibitors can be combined safely
with Viramune.
Viramune can alter the blood levels of various protease inhibitors,
with the blood levels of some being increased and others decreased.
Viramune increases the blood levels of Prezista (darunavir), but no
dosing recommendations for combining these drugs has been
established. Viramune can lower the dose of Norvir (ritonavir)-boosted
Reyataz (atazanavir), Norvir-boosted Lexiva (fosamprenavir) and
Kaletra (lopinavir/ritonavir). For this reason, Kaletra and Norvir/Lexiva
should be used twice-daily when they are combined with Viramune,
while Norvir/Reyataz should not be combined with Viramune at all.
The interaction between Viramune and Norvir-boosted Invirase (saquinavir)
has not been established.
Viramune can interact with some medications used to treat TB, MAC
and other bacterial infections. Rifadin (rifampin) can decrease
Viramune levels (Rifadin should not be used). Mycobutin (rifabutin)
can also decrease Viramune levels (no dose change necessary).
Viramune can also decrease Biaxin (clarithromycin) levels; similarly
Biaxin can increase Viramune levels (an alternative to Biaxin is
recommended).
Viramune can interact with some medications used to treat thrush (candidiasis)
and other fungal infections. Viramune can decrease Nizoral (ketoconazole)
levels in the bloodstream. Similarly, Nizoral can increase Viramune
levels in the bloodstream. Taking these two drugs together is not
recommended. Diflucan (flucanazole) can significantly increase
Viramune blood levels, so caution is warranted and people should
watch carefully for the development of Viramune side effects.
Viramune can interact with oral contraceptives/birth control pills (ethinyl
estradiol). Viramune decreases the amount of ethinyl estradiol in
the bloodstream, which can increase the risk of pregnancy.
Alternative forms of contraception should be used.
If you take methadone, Viramune can decrease the amount of it in
your blood. This might cause you to experience withdrawal symptoms
and may require that your doctor or your rehabilitation program
increase your dose of methadone.
Viramune may decrease the blood levels of a number of medications
used to treat heart problems. These include heart-rythm medications
such as Cordarone (amiodarone), Norpace (disopyramide) and Xylocaine
(lidocaine). It also includes calcium-channel blockers such as
Cardizem (diltiazem), Procardia (nifedipine) and Veralan (verapamil).
Blood levels of Coumadin (warfarin), which is used to prevent blood
clots can also be decreased. No dose adjustments are recommended,
but providers should watch for symptoms that the heart medications
are not working properly.
Viramune may decrease blood levels of drugs used to treat seizures
and other disorders. These include Tegretol (carbamazepine),
Klonapin (clonazepam) and Zarontin (ethosuximide). No dose
adjustments are recommended, but providers should watch for symptoms
that the anti-seizure medications are not working properly.
Viramune may decrease blood levels of drugs used to suppress the
immune system (e.g. after transplantation, or to treat auto-immune
disease such as psoriasis). These include Sandimmune (cyclosporin),
Prograf (tacrolimus), Rapamune (sirolimus). No dose adjustments are
recommended, but providers should watch for symptoms that the
immune-suppressing drugs are not working properly.
It is not yet known what effect Viramune has on blood levels of
Viagra (sildenafil) or Levitra (vardenafil), two drugs used for
erectile dysfunction.
Side
Effects
Liver problems have been
reported in HIV-positive people treated with Viramune. The greatest
risk of liver problems is during the first six weeks of treatment.
Liver problems are more likely to occur in women (including pregnant
women) with CD4 cell counts greater than 250 at the time of starting
HIV treatment for the first time. As for men, liver problems are
more likely to occur if the CD4 cell count is above 400 at the time
of starting HIV treatment for the first time. HIV-positive people
should work with their doctors very carefully if they have CD4 cell
counts above these levels and are planning on starting therapy for
the first time with a drug regimen that contains Viramune.
Because liver problems can be very serious, your doctor should make
sure your liver is healthy—he or she can order simple blood tests to
check for this—before you start taking Viramune. Your doctor should
also test your blood frequently during the first three to four
months of treatment.
In rare cases, liver problems can be very serious and become
life-threatening. Therefore, if you develop any of the following
symptoms, call your doctor immediately: general ill feeling,
tiredness, lack of appetite, yellowing of the skin or eyes,
darkening of the urine, pale stools, liver tenderness.
The most common side effect of Viramune is skin rash. In a small
number of patients, rash has been serious and resulted in death.
Therefore, if you develop a rash with any of the following symptoms,
call your doctor immediately: general ill feeling, fever, muscle or
joint aches, blisters, mouth sores, conjunctivitis (inflammation of
the inner surface of the eyelids), swelling of the face, tiredness.
If you must stop treatment with Viramune because you have these
types of serious reactions, you must not take Viramune again.
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