- Allergy treatment
- Antimicrobials for systemic use
- Antiparasitic drugs
- Cardiovascular system
- Dermatology
- Drugs affecting metabolism
- Drugs used in sensory organ disorders
- Gastrointestinal tract
- Haemopoietic system and blood
- Locomotor system
- Nervous system
- Respiratory system
- Systemic hormones
- Urogenital system and Sexual hormones
Antimicrobials for systemic use
Antivirals
- Antiherpetic and anti-cytomegalovirus preparations
- Flu treatment, broad spectrum antivirals and antiretroviral drugs
Antiviral drugs are preparations used to treat various viral diseases: influenza, herpes, HIV, etc. They are also used for preventive therapy.
By the source and chemical nature, antiviral drugs can be divided into the following groups:
- Interferons of endogenous origin which are obtained through genetic engineering, their derivatives and analogues (human leukocyte interferon, etc.);
- Synthetic compounds (amantadine, arbidol, bromnaphtoquinone, etc.);
- Substances of plant origin (alpisarin, flacosidum, etc.).
Based on the characteristics of main use, antiviral drugs can be divided into several groups:
- antiherpetic (Acyclovir, Valaciclovir, Penciclovir, Famciclovir). The mechanism of action of these drugs is based on the ability to inhibit the action of viral enzymes, by which a virus integrates its genetic code in the affected cells. Antiherpetic drugs actively affect the simple virus curing diseases such as skin herpes, genital herpes, neonatal herpes, chickenpox, encephalitis, pneumonia, etc. Active against Herpes simplex types 1 and 2, herpes zoster virus (Varicella zoster), Epstein-Barr virus. The half-life of antiherpetic medications in general is about 3-4 hours.
Antiherpetic drugs can have rare side effects in form of allergic reactions. These drugs should not be used during lactation. Concomitant use of probenecid with acyclovir causes increase in half-life of Acyclovir.
- anti-cytomegaloviral (Ganciclovir, Foscarnet). These drugs either inhibit the action of enzymes responsible for the integration of viral code or bind with this enzyme and make it incapable. Acting on cytomegalovirus as well as on the herpes virus, they are effective in the treatment of pneumonia, diseases of the gastrointestinal tract and those herpetic infections that are resistant to antiherpetic drugs.
Inhibit cytomegalovirus replication by selective suppression of synthesis of viral DNA. Ganciclovir is usually introduced intravenously. The half-life in plasma is 3.5 h, in the cell - 12 hours, compared with 1-2 h for acyclovir. Ganciclovir for oral administration has a longer half-life (5 h), low bioavailability (8-9%), thus used only in maintenance (suppressive) therapy. Ganciclovir is not metabolized and is excreted by the kidneys.
The anti-cytomegaloviral drugs are contraindicated during pregnancy and breastfeeding, and should be used with caution in patients with renal dysfunction. Treatment with ganciclovir may cause neutropenia (decrease in the number of neutrophils in the blood) and granulocytopenia (decrease in the granulocytes in the blood), thus it is necessary to regularly check the blood picture during the therapy. Anti-cytomegalovirals may affect the cardiovascular system (arrhythmias, fluctuations in the blood pressure level), CNS (depression, obsessive-compulsive disorder, dizziness, insomnia, paresthesia, convulsions), gastrointestinal tract (nausea, vomiting, epigastric pain, anorexia, diarrhea, flatulence, reactive pancreatitis, hepatitis), kidneys (hematuria, increased blood creatinine, metabolic acidosis). Ganciclovir causes thorough suppression of bone marrow function and is a potentially carcinogenic remedy. Foscarnet therapy requires a kidney function check 2-3 times a week during the initial treatment and weekly during maintenance therapy. Foscarnet has a neurotoxic effect and may cause hypocalcemic seizures.
Ganciclovir increases the toxicity of dapsone, pentamidine, vincristine, vinblastine, adriamycin, amphotericin B, co-trimoxazole and trimethoprim.
