Pharmacology Essay

Systems Pharmacology Among Viruses and Bacteria Essay
Hypertension Treatment
The exact causes of essential hypertension are still largely unknown, so the treatment of this health condition is symptomatic. The most influential factors causing the development of hypertension are thought to be environmental and genetic. Depending on the health status of the patient, it is possible to choose among several types of drugs. Major attention should be paid to the presence of heart diseases when developing a hypertension treatment plan.

Medications treating hypertension can be divided into three classes: sympathetically-acting, acting via hormonal control, and vasodilators. Sympathetically acting drugs affect the sympathetic nervous system that releases noradrenaline. The release of α and β receptors causes the increase of blood pressure. Such sympathetically acting drugs as prazosin and phenoxybenzamine block the release of α and β receptors and, thus, decrease blood pressure. The side effects associated with the administration of this type of drugs involve postural hypotension and lethargy.

Hormonally acting medications are also effective in blocking AT synthesis, which results in lower blood pressure. Some examples of these drugs are losartan and captopril. Vasodilation is another part of therapy to treat hypertension that is aimed at the widening of blood vessels. Diuretics are vasodilators that cause the blood vessels widening through the entry of certain elements (for example, Ca2+).

Bendrofluazide, frusemide, and spironolactone are diuretics commonly used to treat hypertension. Calcium channel antagonists (for instance, amlodipine, diltiazem, and nifedipine) are vasodilators that prevent calcium from entering blood cells, which leads to lower blood pressure as well. Potassium channel activators (such as minoxidil) cause the relaxation of muscle cells. Hydralazine can also be prescribed to treat hypertension, but this drug is mainly used in combination with diuretics and some sympathetically acting drugs. Nitrates can be used when treating essential hypertension as they are effective vasodilators.

Antibiotic Classes and Application Use
Antibiotics, also referred to as antimicrobials or antibacterials, are chemical compounds that are utilized to kill or impede the growth of such infectious organisms as bacteria and fungi. Antibiotics can be natural substances, but they are often synthesized or derived from natural substances. Natural penicillins include penicillin G (Benzyl) and penicillin G sodium and potassium. Semisynthesized penicillins are penicillinase-resistant penicillins (cloxacillin), aminopenicillins (ampicillin), and antipseudomonal penicillins (carbenicillin indanyl sodium). The primary feature shared by all antibiotics is their selective toxicity, which is their ability to be more toxic to infectious organisms and remain comparatively safe for the host organism.

Antibiotics can be divided into two groups based on the spectrum of their activity. Antibacterials of the broad spectrum activity can affect a large number of pathogens while narrow-spectrum-activity antibiotics can have an influence on particular infectious organisms. Antipseudomonal penicillins are characterized by the broadest spectrum. Antimicrobials are also grouped in terms of their impact into bactericidal (those killing pathogens) and bacteriostatic (those impeding the growth of these organisms).

Before prescribing antibiotics, it is essential to consider two aspects: patients’ history and the type of the organism attacking them. As for the data regarding the patient, it is important to identify their allergies (if any), infection susceptibility, disorder severity, ethnicity, age, pregnancy, breastfeeding, and the use of other types of medication. Antibiotics are effective against gram negative and gram-positive bacteria, acid-fast bacteria, as well as anaerobic and anaerobic bacteria.

Antibiotics are commonly used to treat such health issues as typhoid fever, invasive salmonellosis, peritonitis, endocarditis, chronic bronchitis and pneumonia, meningitis caused by bacteria, lower urinary tract infection, gonorrhea, urethritis, syphilis, and septicemia. Antimicrobials are also effective in treating osteomyelitis, conjunctivitis, dental infections, otitis media, acne, and animal or insect bite.

Virus Infection and Treatment
Viruses are infectious agents that cause diseases and can live and replicate in host cells (animals, plants, or bacteria). These organisms have a core with RNA or DNA that is enclosed in a protein shell. Some examples of virus types are influenza A and B, hepatitis B and C, herpes, papilloma, and human immunodeficiency (HIV). Some viruses such as Epstein-Barr virus, hepatitis B and C, human papillomavirus, and herpesvirus 8 can cause cancer.

The major classes of anti-viral medications are as follows: fusion, protease, viral DNA polymerase, nucleoside reverse transcriptase and non-nucleoside reverse transcriptase, and integrase inhibitors. Inhibitors of viral coat disassembly and chemokine receptor antagonists are also widely used anti-viral drugs. Different antivirals have a specific mechanism of action and are prescribed accordingly. For instance, such antivirals as docosanol or maraviroc (fusion inhibitors) block the fusion of the virus and the host cell. Uncoating inhibitors (such as rimantadine or amantadine) prevent viral RNA genome release.

Integrase inhibitors block HIV DNA insertion into the DNA of CD4 cell. Viral DNA polymerase inhibitors terminate viral DNA chain and are effective against such agents as varicella-zoster virus or herpes. Nucleoside and nucleotide reverse transcriptase inhibitors block the conversion of viral RNA into DNA, which is a disruption of the process of retroviruses functioning. Late protein synthesis is blocked by protease inhibitors while assembly is blocked by neuraminidase inhibitors. Neuraminidase inhibitors block the release of virions from infected cells surface. Protease inhibitors facilitate the production of inactive viral proteins that are instrumental in preventing the maturation of virions, which results in their inability to infect other cells.

Genital Infections and Treatment
Genital infections are often sexually transmitted and can be caused by viruses, bacteria, or fungi. People can also be infected through touch, sharing things with an infected person, or due to inappropriate hygiene. When a person is diagnosed with a genital infection, they are advised to inform all their sexual partners about their health condition, which will enable all of the stakeholders to identify certain health issues timely.

Herpes is one of the common genital infections that can affect both males and females. The symptoms associated with this health condition include red areas with or without itching or tingling. The appearance of blisters and transformation into painful sores is another symptom. Herpes causes pain during urination, as well as headaches, fever, and fatigue. This disease is caused by such agents as herpes simplex virus 1 and 2, Varicella-zoster virus, and cyto megalo virus. Aciclovir is the most effective medication to treat herpes, but lignocaine and paracetamol are prescribed in addition to acyclovir in order to accelerate recovery.

Gonorrhea is a genital infection that is caused by bacteria. This infection is characterized by such symptoms as increased frequency and urgency of urination, redness and swelling of genitals, greenish, yellow, or white discharge. When treating this health issue, ceftriaxone and azithromycin are prescribed. The latter is often administered to treat chlamydia that is also a genital infection that is commonly present in people diagnosed with gonorrhea. Candidiasis is a widespread genital infection that is caused by fungi. The symptoms of this disease are itching, soreness, swelling around genitals, pain and burning during sex or urination. Such antifungal drugs as imidazole and fluconazole are effective medications for women while male patients are prescribed imidazole.

Gastrointestinal Infections and Treatments
Helicobacter pylori infection, known as the central cause of ulcers, is a bacterium that is mainly located in mucosa on gastric epithelium luminal surface. These bacteria can live in a human body for years without the appearance of any significant symptoms. However, when symptoms occur, they include pain in abdomen, nausea, appetite loss, bloating, and weight loss. By producing urease, they ensure their survival in the acidic environment. These bacteria damage stomach tissues due to their secretion causing the development of ulcers. This infection is the most common disease found in up to 90% of people having ulcers.

The primary goals of treatment include ulcer healing, H. pylori eradication, and symptoms relief. The patients are prescribed gastric acid inhibitors, antacids, and cytoprotection. Such antacids as alkaline salts reduce the acid load, which results in the neutralization of gastric acidity. Colloidal antacids decrease acidity and provide a mechanical coating to ulcers. Acid inhibitors (such as cimetidine and ranitidine) decrease and impede acid secretion. Cytoprotection is an important part of treatment as drugs facilitating mucosal resistance stimulate mucus and the secretion of hydrogen carbonate improving the protective function of mucus.

The use of medication against H. pylori is an important component of treatment as well. The use of the triple therapy ensures the eradication of the bacteria in question in one week with no or limited side effects. High patient compliance is another feature of this type of treatment. This therapy involves the administration of amoxicillin, clarithromycin, and proton pump inhibitors. Importantly, the use of these drugs triggers immune responses on the local and systemic levels.