Fomivirsen (Intraocular)

Overview

While fomivirsen cannot cure the infection caused by cytomegalovirus (CMV) retinitis, it can act to prevent the symptoms caused by the infection from becoming any worse. This medication is available only by prescription, and since it must be injected into the eye, it must always be administered by a qualified medical professional.

The most common brand name under which fomivirsen is marketed is Vitravene, it is a sodium intravitreal injectable solution which must be very carefully administered to a patient. The infection which is being treated is one frequently sustained by persons whose immune system has been compromised, often those patients having acquired immunodeficiency syndrome (AIDS).

An ophthalmologist would have to diagnose CMV retinitis, and this is determined following a very thorough examination of the eye's retina, to include indirect ophthalmoscopy. This diagnosis must be cautious and comprehensive since there are other medical conditions which can approximate the same symptoms as CMV retinitis. These include:

  • Retinal scars
  • Ocular infections caused by syphilis, histoplasmosis, toxoplasmosis, candidiasis, varicella-zoster virus, and herpes-simplex virus
  • Cotton wool spots.

Condition Treated

  • Cytomegalovirus Retinitis

Type Of Medicine

  • Anti-viral

Side Effects

While it can help reduce the symptoms of CMV retinitis, fomivirsen ophthalmic can also have some undesirable side effects for some patients, and these can vary in intensity from the very mild to quite severe. Some patients experience none of these side effects whatsoever, while others will, unfortunately, experience some of the worst of them. If you happen to experience side effects from taking this medication which are severe enough to cause discomfort, you should notify your doctor so that some kind of treatment can be established.

The first and potentially one of the most severe side effects to be concerned about is an allergic reaction, and the reason this is of such concern is that there is a potential for the side effects to become extremely severe, and even life-threatening. Although this level of intensity is extremely rare, it can happen, and it is, therefore, something to be on the alert for. Some of the most prominent symptoms of an allergic reaction include the following:

  • Extreme itchiness at various sites around the body
  • The appearance of rashes and/or hives on the skin
  • Difficulty with breathing, often including a sensation of tightness in the chest
  • Lightheadedness or dizziness
  • Swelling or puffiness which appears around the eyelids, or in the throat, lips and tongue.

Another group of side effects which is fairly common in occurrence includes a number of reactions affecting the eyes, which is understandable because the medication itself is injected into the eye. That group of side effects is comprised of the following:

  • Watery eyes
  • The appearance of a veil or curtain which seems to obscure your vision
  • Blurry vision
  • A change in how colors appear to you
  • Pain radiating around the eyes
  • Redness of the eyes
  • Seeing floating spots
  • Flashes or sparks of light which appear to your eyes
  • Extreme sensitivity to light
  • Decreased vision and other changes in the way that you see.

A less common group of side effects can occur as well, with these affecting a far lesser number of patients, but still possible.

  • Soreness around the eyes
  • Itching, soreness, or redness at the precise site of injection
  • Pain during any kind of eye movement
  • Swelling around the eyes
  • Decreased peripheral vision when attempting to look forward.

There are a wide range of other very minor side effects which may potentially occur for patients being treated with fomivirsen ophthalmic, and these will generally subside of their own accord within a few hours or a day after a patient has been treated. Some of the most prominent of those side effects and the ones most frequently occurring are:

  • Unusual weakness or tiredness
  • Nausea and/or vomiting
  • Diarrhea
  • Abdominal pain or cramping
  • Skin rashes
  • Headaches
  • Stomach pain or cramping
  • Tightness in the chest
  • Temporary weight loss
  • Profuse sweating
  • Persistent coughing
  • Intense pain in the lower back
  • Loss of appetite.

Dosage

It should be remembered that no dosage of fomivirsen ophthalmic will cure CMV retinitis, although it will generally work well to reduce ocular infections. It will not operate on any symptoms of CMV which occur elsewhere in the body, for instance in the lungs or in the colon. Also, the dosages discussed below are not intended to be considered as definitive dosages for all patients ' your own appropriate dosage level will be determined by your doctor after he/she considers a number of factors. These factors can include some or all of the following:

  • Your personal medical condition
  • The strength of the medication
  • The frequency of administration
  • The total duration of the time frame for which you are given this drug
  • The severity of CMV retinitis in your case
  • Your tolerance to the drug.

For adults being treated with fomivirsen ophthalmic via localized ocular injection, a standard initial dosage would be 330 micrograms, injected on alternating weeks, for a total of two doses. If necessary, this initial treatment can be followed up by additional doses spaced four weeks apart, and at the same dosage level. No standardized dosage level has been established for pediatric patients, so this would be determined on a case-by-case basis, per the direction of a family doctor.

Interactions

Some drugs will have interactions with other medications, either producing unwanted side effects in the patient, or diminishing the effectiveness of one or both medications involved. In order to avoid these kinds of developments, it is advisable for you as a patient to prepare a list of all over-the-counter drugs, prescription medications, vitamins, and herbal supplements which you are currently taking, as well as the dosage levels of each. Your doctor can review this list and make a determination whether there is a potential for any interaction between these drugs and fomivirsen ophthalmic.

The list you make can be useful in other ways as well. Should you ever need to go to an emergency room for unscheduled treatment of a medical condition, you can show this list to the doctor there, and that will allow him/her to safely prescribe treatment for the medical condition you have.

The two drugs which are known to interact with fomivirsen ophthalmic, and which are most commonly checked for by doctors are the following:

  • Cidofovir
  • Vistide.

In addition to interactions with other medications, sometimes usage of a specific drug must be taken into serious consideration because it can have an impact on a medical condition you already have. In the case of fomivirsen ophthalmic, the only known medical condition it has an impact with is glaucoma, so if you have glaucoma, it is entirely possible that your doctor will recommend against using fomivirsen, or will attempt to administer the drug in reduced dosages to hopefully achieve similar results.

Warnings

There are a few precautions which should be observed by patients for whom fomivirsen is being considered as a treatment program. First of all, this medication will not affect symptoms of CMV which appear elsewhere in the body ' it will only help with ocular symptoms. This medication should be avoided by patients who have recently been treated with intravenous or intravitreal cidofovir, since it may trigger inflammation, or worsen inflammation which already exists around the eyes.

It is possible that inflammation will occur around the eyes after being treated with fomivirsen, and in such cases, it may be necessary to manage the inflammation with some kind of corticosteroid. Some patients have also experienced an increase in intraocular pressure after treatment, although this generally subsides within hours of treatment, without any kind of intervention.

While there is no research or available data which would rule out being treated with fomivirsen for women who are pregnant or are considering breastfeeding, it should be remembered that both pregnancy and breastfeeding carry significant risks to a fetus for AIDS patients. Since most patients who are treated with fomivirsen are in fact, AIDS patients, the notion of pregnancy and breastfeeding are two areas that should be strongly considered before proceeding. While there is little or no additional risk to the mother, the risk to an unborn fetus and the risk to a nursing infant are considerable for any AIDS patient.

Storage

Fomivirsen ophthalmic will be stored in a clinical setting, by medical professionals, and will not be administered at home, so there are no storage guidelines necessary for patient consumption. It will also be disposed of according to recognized disposal protocols in these institutions when that becomes necessary.

Summary

Fomivirsen ophthalmic is a drug used primarily in the treatment of AIDS patients who have developed an ocular infection known as CMV retinitis, and the delivery method of this medication is an injection at a site close to the eye itself. This drug will not treat symptoms of CMV which occur at sites around the body, other than in the eyes.

While there are very few interactions with other drugs, there are some fairly common side effects associated with usage of fomivirsen, many of which affect the eyes. This drug will be administered in a clinical setting and is not one which can be self-administered at home, so all issues connected with storage, usage, and disposal will be handled by qualified medical personnel.