How fast does Zostex® work?
Zostex® is taken in tablet form, which means that the active ingredient only reaches its destination after digestion and absorption. The earlier treatment with Zostex® is started, the faster the symptoms are relieved. Overall, Zostex works quite quickly. After about half a day, an improvement can be seen. It usually takes several days for the symptoms to subside completely.
Dosage of Zostex®
As a rule, Zostex ® is dosed as follows: Take one tablet (125mg) daily for one week. The intake can be taken independently of meals. However, it is recommended to swallow Zostex ® always at the same time of day with plenty of water.
Contraindications – When should Zostex® not be given?
Caution: Zostex® should never be taken if any medication containing 5-fluoropyrimidine or 5-fluorouracil has been taken in the last 4 weeks. This also applies to ointments or creams containing the above-mentioned ingredients. Zostex® must not be taken by children and adolescents under 18 years of age. It must not be taken during pregnancy and lactation and in case of hypersensitivity to the active ingredient Brivudine or other ingredients of Zostex®. Zostex® must not be taken during pregnancy or while breast-feeding.
Side Effects of Zostex
The most common side effect of Zostex® is nausea. Occasionally, if side effects are noticed while taking Zostex®, the treating physician should be informed.
- Changes in blood count,
- Impairment of the liver,
- Allergic reactions,
- Gastrointestinal complaints,
- Tiredness,
- Loss of appetite,
- Vertigo,
- Fear,
- Insomnia and
- Sensations of discomfort.
Fatigue occasionally occurs when taking Zostex®. Approximately 1 person in 100 taking the medication is affected by this side effect.
Interaction of Zostex
Zostex® and 5-fluoropyrimidines and 5-fluorouracil (often abbreviated as 5-FU) interact in a life-threatening way. Patients receiving chemotherapy should not be treated with Zostex® under any circumstances.At least 4 weeks must have passed between the last administration of the chemotherapeutic agent and the intake of Zostex®. External preparations (ointments, creams, eye drops, etc.)
containing 5-FU must not be used in combination with Zostex®. The 5-fluoropyrimidine-containing drugs also include capecitabine (Xeloda®), tegafur (UFT® hard capsules), flucytosine (Ancotil®). It is therefore necessary to inform the treating physician of all medications that are taken regularly or have been prescribed in the last six months.
There are no known interactions between Zostex® and food. However, since there are occasional side effects on the liver and the breakdown of alcohol also takes place in the liver, it is advisable as a precaution not to consume alcohol while taking Zostex®. At present, there are no known interactions between the contraceptive pill and Zostex®.
However, since there are various active ingredients of the pill, the doctor and pharmacist should be consulted. Currently, no interactions between Zostex® and antibiotics are known. However, if other medications are taken in addition to Zostex®, it is imperative that the doctor treating the patient be informed.