If chemoprophylaxis is induced, physicians administer a viral agent or antibiotic to the patient to prophylactically (preventively) treat an established or an impending infection. The administration of these drugs is intended to prevent or combat the spread of pathogens in the body.
What is chemoprophylaxis?
If chemoprophylaxis is induced, physicians administer a viral agent or antibiotic to the patient to prophylactically (preventively) treat an identified or a threatened infection. Medical professionals have various forms of prophylaxis at their disposal: according to the microorganism, the time of use and the indication. Chemoprophylaxis involves drug-based protective measures in the form of tablets or vaccinations. These treat an existing infection or prevent it if the pathogens have not yet spread in the human organism. The drugs kill the pathogens in the blood, provided that the patient has no resistance to the substance used. Tablets cannot prevent some types of infection, such as malaria, but they can kill the pathogens. With the increasing number of pathogen resistances, a residual risk remains for some infectious diseases, as no complete drug protection exists. The allocation of the right drug depends on individual patient factors such as health status, age, previous illnesses, resistance, and any allergies to individual components of the substances.
Function, effect, and goals
When indicated by microorganism, the physician administers antibacterial and antiviral chemoprophylaxis. By time of use: with preexposure prophylaxis, patients who have HIV infection take antiviral drugs to eliminate or at least minimize a risk situation, such as unprotected sex. Post-exposure prophylaxis (PEP) is administered to patients in the presence of contamination with pathogens to prevent further spread in the organism. Such an infection can occur, for example, in the hospital when contact is made with inadequately sterile equipment such as a syringe. In addition, the spread of the infectious disease to other people must be prevented. This type of prophylaxis takes the form of anti-viral drugs or antibiotics. Vaccination is also possible if the patient is at risk of rabies from an animal bite. Perioperative chemoprophylaxis in case of surgical interventions and operations prevents inflammation of larger wound areas and washing of pathogens (germs, bacteria) into the bloodstream. Malaria prophylaxis is given according to the time of indication in order to prevent infection with malaria infection. Exposure prophylaxis protects against transmission of disease by insects. Stand-by prophylaxis has a long-term effect. Patients suffering from recurrent urinary tract infections are treated with antibiotics. Chemoprophylaxis is used for various diseases and pathogens: tuberculosis, malaria, meningitis, pertussis (whooping cough) and meningococci. Meningococcal disease (Neisseria meningitidis) occurs when the pathogens settle in the nasopharynx. People with a healthy immune system do not show clinical symptoms when these pathogens are present. The body is able to break down these pathogens on its own. The pathogens die rapidly outside the site of infection, so very close interpersonal contact and transmission of oropharyngeal secretions are necessary for transmission and infection. The disease takes the form of meningitis and is usually characterized by sepsis. In particularly severe cases, septic shock may occur. Headache, chills, fever and a severe feeling of illness are the accompanying symptoms. The mortality rate is particularly high in infants, young children, and the elderly. Meningitis can lead to irreversible brain damage. Septic courses of disease can cause persistent disability, limited necrosis, and extensive gangrene of the limbs in severe cases. Meningitis can lead to cerebral palsy, seizures, hemiplegia, damage to the inner ear, deafness, impaired intellectual abilities, and hydrocephalus.The mortality rate in Germany is 1 percent in the presence of meningitis; in the case of an additional septic course, the mortality rate increases to 13 percent, and in the case of Waterhouse-Friderichsen syndrome to 33 percent. Regular vaccinations as early as childhood have largely curbed whooping cough caused by the pathogen Bordetella pertussis. However, there is a cyclical increase in pertussis every four to six years. In 2013, mandatory reporting was introduced. Infection with the pathogen occurs through the respiratory tract, and multiplication occurs through the mucous membranes. A large number of toxins deteriorate the defenses of the immune system. The disease is characterized by cough, fever and weakness. The wheezing typical of the disease occurs due to the sudden inspiration of a closed glottis as the attack draws to a close. Tuberculosis is an infectious disease that is common throughout the world. It is caused by mycobacteria and mainly affects the lungs. Spread to other organs and the respiratory tract is possible. This disease leads the worldwide mortality statistics. Infection occurs by droplet infection as in common colds. If germs are detected in sputum, overt tuberculosis is present. If external body secretions are carriers of the germs, physicians speak of potentially open tuberculosis.
Risks, side effects, and hazards
Prophylactic use of virustatics and antibiotics is induced only in rare cases to prevent serious infectious diseases. Prophylaxis is used mainly for those diseases where vaccination is not possible and preventive measures are useful, such as malaria. The drugs used are chenine, chloroquine, mefloquine, hydroxychloroquine, atoquavone and proguanil. Meningococcal infection is treated with penicillin G. However, patients receive additional continuing therapy with ciprofloxacin, rifampicin, or ceftriaxone before discharge from the hospital because the antibiotic alone does not kill the pathogens. Eradication of whooping cough is not possible to date, since even vaccinated people can become ill. For basic immunization, anticellular vaccines are available, which are combined with antigens. Chemoprophylaxis is based on macrolides. Tuberculosis diseases are treated with drugs specifically designed for these pathogens, which are therefore called antituberculotics. They are administered in the form of primary prophylaxis. Children receive 200 mg/m2 KOF and adults 300 mg/day of isoniazid. Taking prophylactic drugs can lead to resistance of the drug used, which complicates treatment. To date, only one government recommendation exists for treatment with chemoprophylactic drugs: for workers who regularly come into contact with poultry and who are at risk of contracting avian influenza or avian flu. Employers are advised to provide chemoprophylaxis with neuraminidase inhibitors to their employees. Preventive treatment with oseltamivir phosphate (Tamiflu) is also possible as protection against avian influenza and influenza if adequate influenza vaccine is not available.
