Pharmacology PDF

PHARMACOLOGY PRAZIQUENTEL PAMOATE: ANTHELMINTIC - For giant roundworms, hookworm Helminths are large parasitic worms that live and pin wor...

PHARMACOLOGY PRAZIQUENTEL PAMOATE: ANTHELMINTIC - For giant roundworms, hookworm Helminths are large parasitic worms that live and pin worm and lay eggs in warm, moist soil where sanitation and hygiene are poor. SIDE EFFECTS AND ADVERSE EFFECTS: - These parasites cause disability and - The common side effects of developmental delays in children and anthelmintics (agents that destroy adolescents. worms) include various manifestation of GI distress, such as GROUPS OF HELMINTHS INCLUDE: anorexia, nausea, vomiting, and o Cestodes (tapeworms) occasionally diarrhea and stomach o Trematodes (flukes) cramps o Intestinal nematodes (roundworms) o Tissue-invading nematodes (tissue - The neurologic problems associated roundworms and fibriae) with anthelmintics are dizziness, weakness, headache, and - They enter the human host via drowsiness. contaminated food, bites of carrier insects, or direct penetration of the - Adverse reactions do not occur skin frequently because the drugs usually are given for a short period (1 to 3 days) IVERMECTIN: PEPTIDES - for headlice only - The center for communicable - Apply to affected area, avoid disease, a governmental health contacts with eyes and mouth agency that prevents and reduces communicable diseases in the United States and globally, has launched an BITHIONOL: initiative for health care providers - Effective against flukes if the patient and patients to prevent drug- can’t receive praziquantel due to resistant infection resistance or adverse effects - Antibiotic therapy is challenged by increasing occurrence of drug- PRAZIQUANTEL: resistant infections such as Methicillin-Resistant Staphylococcus - For the treatment of beef, pork and Aureus (MRSA) and Carbapenems- fish tapeworms Resistant Enterobacteriaceae (CRE). - Blood flukes  PHARMACOLOGY - Antimicrobial Peptides provide a SERIOUS REACTIONS: include broad spectrum and bactericidal nephrotoxicity, neurotoxicity, neuromuscular ability to kill a range of parasites and blockade, respiratory distress, apnea, viruses superinfection and C. difficile associated diarrhea. PEPTIDES CLASSIFICATION: - Acute respiratory distress syndrome can occur when the antibiotic is o Antiviral administered by inhalation. o Antimicrobial o Antifungal o Antiparasitic POLYMYXINS - Polymyxins were one of the early groups of antimicrobials, but many of 2 GROUPS OF PEPTIDES USED AS the early drugs were discontinued ANTIBIOTICS because of severe toxic reactions such as neurotoxicity and o Polymyxins nephrotoxicity. o Bacitracin - Polymyxins are polypeptide antibiotics that consist of five COLISTIMETHATE different chemical compounds, polymyxins A through E. - Colistimethate is a polypeptide antibiotic that targets aerobic gram- - Currently, polymyxin B and negative bacteria. polymyxin E (also known as colistin) are used in clinical practice. - It is used to treat Pseudomonas aeruginosa, CRE, Klebsiella and - Polymyxins produce a bactericidal Shigella species. effect by interfering with the cell membrane of the bacterium, thereby - This antibiotic has the capacity to causing cell death. penetrate and disrupt the bacterial cell. - They affect most gram-negative bacteria, such as P. aeruginosa, - Colistimethate is available in forms Escherichia coli, Klebsiella and administrated IM, intravenously (IV), Shigella species. and by inhalation. - The polymyxins are not absorbed through the oral route except for COMMON REACTIONS: include dyspepsia, colistin, which exerts action on the tingling, slurred speech, dizziness, colon and is excreted in the feces. paresthesia, pruritus, rash and fever.  PHARMACOLOGY - Bacitracin is not absorbed by the GI - Intramuscular injection of tract; polymyxins produces intense pain at the injection site. Consequently, - OTC bacitracin ointment is available parenteral polymyxins are for application to the skin. administered at a slow IV infusion rate. - THE SIDE EFFECTS: of bacitracin include skin redness and rash, nausea, and vomiting. SEVERE ADVERSE EFFECTS : - SEVERE ADVERSE REACTIONS: - High serum levels of polymyxins can are renal damage and ototoxicity, cause nephrotoxicity and and mild to severe allergic reactions neurotoxicity. that range from hives to anaphylaxis may occur. - In nephrotoxicity, the blood urea nitrogen (BUN) and serum creatinine levels are elevated, METRONIDAZOLE: - Metronidazole is a synthetic SIGNS AND SYMPTOMS OF antibiotic and antiprotozoal NEUROTOXICITY: (nitroimidazole class) that works by disrupting the bacterial DNA and - (Toxicity of the nerves) include inhibiting cell synthesis, which causes paresthesia - abnormal sensations such as numbness, tingling, burning, cell death. and prickling-and dizziness. - Metronidazole as a protozoal treats Trichomonas vaginalis, amebiasis, - Neurotoxicity is usually reversible and giardiasis; as an antibiotic, it is when the drug is discontinued. used for anaerobic bacteria, including Helicobacter pylori, a pathogen in GI infections. BACITRACIN - TOXIC REACTIONS: include - Bacitracin has a polypeptide neurologic disturbances such as structure and acts by inhibiting seizures and peripheral neuropathies bacterial cell wall synthesis and damaging the cell wall membrane, which results in death of the cell. - The drug action can be bacteriostatic or bactericidal.  PHARMACOLOGY ANTI-INFLAMMATORY AGENTS NSAID (NONSTEROIDAL ANTI- INFLAMMATORY DRUG) - Anti-inflammatory also relieve pain (analgesic), reduce elevated body - These drugs may be called temperature (antipyretic), and prostaglandin inhibitors with varying inhibit platelet aggregation degrees of analgesic and antipyretic (anticoagulant). effects, but they are used primarily as anti-inflammatories to relieve - Aspirin is the oldest anti- inflammation and pain. inflammatory drug, but it was first used for its analgesic and antipyretic - With several exceptions, NSAID properties. preparations are not suggested for use in alleviating mild headaches and mildly elevated temperature. - Preferred drugs for headaches and fever are aspirin (adults only for fever), acetaminophen, and ibuprofen. - NSAIDs are more appropriate for reducing swelling, pain, and stiffness in joints. 7 GROUPS OF NSAID: o Salicylates o Para-chlorobenzoic acid derivatives, or indoles o Phenylacetic acids o Propionic acid derivatives o Fenamates o Oxicams - Drugs such as aspirin inhibit the o Selective Cox-2 inhibitors biosynthesis of prostaglandin and are therefore called prostaglandin inhibitors. Because prostaglandin SALICYLATES inhibitors affect the inflammatory process, they are more commonly - Aspirin is also called acetylsalicylic called anti-inflammatories or anti- acid (ASA) let the acetyl group used inflammatory drugs. in its composition.  PHARMACOLOGY - The abbreviation frequently used for - In asthmatic patients - are symptoms aspirin is ASA. of aspirin overdose or hypersensitivity to aspirin. - Aspirin was developed in 1899 by Adolph Bayer, making it the oldest anti-inflammatory agent. PARA-CHLOROBENZOIC ACID - One of the first NSAIDs introduced - It was the most frequently used anti- was indomethacin, a para- inflammatory agent before the chlorobenzoic acid. introduction of ibuprofen. - It is used for rheumatoid arthritis - Aspirin is a prostaglandin inhibitor (RA), gouty arthritis, and that decreases the inflammatory osteoarthritis and is a potent process. prostaglandin inhibitor. - It is also considered an antiplatelet - It is highly protein bound (99%) and drug for patients with cardiac or displaces other protein-bound drugs, cerebrovascular disorders; aspirin resulting in potential toxicity. decreases platelet aggregation, and thus blood clotting is decreased. - It has a moderate half-life (2.6 to 11.2 hours). - EC tablets should not be crushed or broken. - Indomethacin is very irritating to the stomach and should be taken with - Aspirin has a short half-life. food. - It should not be taken during the last trimester of pregnancy because it PHENYLACETIC ACID DERIVATIVES could cause premature closure of the ductus arteriosus in the fetus. - Diclofenac sodium, a phenylacetic acid derivative, has a plasma half-life - The onset of action for aspirin is of 2 hours. Its analgesic and anti- within 30 minutes. It peaks in 1 to 2 inflammatory effects are similar to hours, and the duration of action is those of aspirin, but it has minimal to an average of 4 to 6 hours. no antipyretic effects. - Patients may be hypersensitive to - It is indicated for RA, osteoarthritis. aspirin. Tinnitus (ringing in the ears), vertigo (dizziness), and - Diclofenac is available in oral, bronchospasm-especially. extended-release, and topical 1% gel preparations.  PHARMACOLOGY - SIDE EFFECTS AND ADVERSE - Ibuprofen is the most widely used REACTIONS: are similar to those of propionic acid NSAID, and it may be other NSAIDs, with far less purchased OTC in lower doses (200 detrimental reactions when using a mg). topical preparation. FIVE OTHER PROPIONIC ACID - Ketorolac, another phenylacetic acid AGENTS derivative, is the first injectable o fenoprofen calcium, NSAID. o naproxen, o ketoprofen, - It inhibits prostaglandin synthesis, o flurbiprofen, and but it has greater analgesic o oxaprozin. properties than other anti- inflammatory agents. PHARMACOKINETICS: - Ketorolac is recommended for short- Ibuprofens are well absorbed from term management of pain. the GI tract. The drug is metabolized in the liver to inactivate metabolites and is excreted - For postsurgical pain, it has shown as inactive metabolites in the urine. analgesic efficacy equal or superior PHARMACODYNAMICS: to that of opioid analgesics. Ibuprofen inhibits prostaglandin - It is administered intramuscularly in synthesis and are therefore effective in doses of 30 to 60 mg every 6 hours alleviating inflammation and pain. They have for adults: a short onset of action, peak concentration time, and duration of action. It may take - Ketorolac is also available in oral, several days for the anti-inflammatory effect intravenous (IV), and intranasal to be evident. preparations. Ibuprofen can increase the effects of warfarin, sulfonamides, many of the PROPIONIC ACID DERIVATIVES cephalosporins, and phenytoin, it should be avoided with these drugs. - The propionic acid group is a relatively new group of NSAIDs. Hypoglycemia may result when These drugs are aspirin-like but have ibuprofen is taken with insulin or an oral stronger effects and create less GI hypoglycemic drug, and risk of toxicity is high irritation. when ibuprofen is taken concurrently with calcium channel blockers. - Propionic acid derivatives are better tolerated than other NSAIDs. Gastric upset occurs, but it is not as severe as with aspirin and indomethacin.  PHARMACOLOGY FENAMATES SELECTIVE COX-2 INHIBITORS - The fenamate group includes potent - Most NSAIDs are nonselective NSAIDs used for acute and chronic inhibitors that inhibit COX-1 and arthritic conditions. COX-2. - As with most NSAIDs, gastric - By inhibiting COX-1, protection of the irritation is a common side effect; stomach lining is decreased, and patients with a history of peptic ulcer clotting time is also decreased, which should avoid taking fenamates. may benefit the patient with cardiovascular or coronary artery - OTHER SIDE EFFECTS: include disease (CAD). edema, dizziness, tinnitus, and pruritus. - Selective COX-2 inhibitors are the drugs of choice for patients with - TWO FENAMATES severe arthritic conditions who need o meclofenamate sodium high doses of an anti-inflammatory monohydrate drug, because large doses of NSAIDs o mefenamic acid. may cause peptic ulcer and gastric bleeding. - Currently, only one drug, celecoxib, OXICAMS is classified as a COX-2 inhibitor. - Piroxicam and meloxicam, oxicams, are indicated for long-term arthritic conditions such as RA and CORTICOSTEROIDS osteoarthritis. - Corticosteroids such as prednisone, prednisolone, and dexamethasone - They too can cause gastric problems are frequently used as anti- such as ulceration and epigastric inflammatory agents. distress, but the incidence is lower than for some other NSAIDs. - This group of drugs controls inflammation by suppressing or - Oxicams are well tolerated, and their preventing many of the components major advantage over other NSAIDs of the inflammatory process at the is their long half-life, which allows injured site. them to be taken only once daily. - When discontinuing long-term steroid therapy, the dosage should be tapered over a period of 5 to 10 days.  PHARMACOLOGY ANTIGOUT DRUGS ANTIGOUT DRUGS: - Gout is an inflammatory condition COLCHICINE: that attacks joints, tendons, and other tissues. It may be called gouty - The first drug used to treat gout was arthritis. colchicine, introduced in 1936. - THE MOST COMMON SITE: of - It is effective in alleviating acute acute gouty inflammation is at the symptoms of gout, but it is not joint of the big toe. effective for decreasing inflammation that occurs in other inflammatory - Gout is characterized by a uric acid disorders. metabolism disorder and a defect in purine (products of certain proteins) - Colchicine does not inhibit uric acid metabolism, which results in an synthesis and does not promote uric increase in urates (uric acid salts) and acid excretion. an accumulation of uric acid (hyperuricemia) or an ineffective - It should not be used if the patient clearance of uric acid by the kidneys. has a severe renal, cardiac, or GI problem. - Uric acid solubility is poor in acid urine, and urate crystals may form, - Gastric irritation is a common causing urate calculi. problem, so colchicine should be taken with food. - Gout may appear as bumps in the subcutaneous tissue of earlobes, - With high doses, nausea, vomiting, elbows, hands, and at the base of the diarrhea, or abdominal pain occurs in great toe. approximately 75% of patients taking the drug. - To promote uric acid excretion and to prevent renal calculi, fluid intake - Colchicine is well absorbed in the GI should be increased while taking tract, and its peak concentration antigout drugs. time is within 2 hours. Most of the drug is excreted in the feces, but - Food high in purine-such as organ 10% to 20% is excreted in the urine. meats, sardines, salmon, gravy, liver, and meat soups and alcohol, especially beer, should be URIC ACID BIOSYNTHESIS INHIBITORS avoided. Alcohol causes both an - Allopurinol, first marketed in 1963, is overproduction and underexcretion not an anti-inflammatory drug; of uric acid. instead, it inhibits the final steps of uric acid biosynthesis and therefore lowers serum uric acid levels,  PHARMACOLOGY preventing the precipitation of an relieving symptoms of gout and attack. inhibiting uric acid reabsorption, small doses of colchicine should be - This drug is frequently used as a given before adding probenecid. prophylactic to prevent gout, and it is a drug of choice for patients with - If gastric irritation occurs, probenecid chronic tophaceous gout. should be taken with meals. It has an average half-life of 1.7 to 31.2 hours - Allopurinol is also indicated for gout and is 34% to 44% protein bound. patients with renal impairment. - PHARMACOKINETICS: Eighty OPIOID ANALGESICS percent (80%) of allopurinol is - Opioid analgesics, called opioid absorbed from the GI tract. The half- agonists, are prescribed for life of the drug itself is 1 to 2 hours, moderate and severe pain. and it is 20 to 24 hours for its active metabolites. - The protein-binding percentage is MORPHINE unknown. Approximately 80% to 100% of allopurinol and its - Morphine, an extraction from opium, metabolites are excreted in urine. is a potent opioid analgesic - Morphine is effective against acute URICOSURICS pain resulting from acute myocardial infarction (AMI) and cancer, relieves - Uricosurics increase the rate of uric dyspnea resulting from pulmonary acid excretion by inhibiting its edema; and may be used as a reabsorption. preoperative medication to relieve anxiety. - These drugs are effective in alleviating chronic gout, but they - Although it is effective in relieving should not be used during acute severe pain, it can cause respiratory attacks. depression, orthostatic hypotension, urinary retention, constipation - PROBENECID is a uricosuric that resulting from reduced bowel has been available since 1945. motility, and cough suppression. - It blocks the reabsorption of uric acid - An antidote for morphine excess or and promotes its excretion. overdose is the opioid antagonist naloxone. - Probenecid can be taken with colchicine. To begin initial therapy for  PHARMACOLOGY MEPERIDINE Usually a loading dose (e.g., 2 to 10 mg of morphine) is given initially to - One of the first synthetic opioids, achieve pain relief. meperidine became available in the mid-1950s. - Within predetermined safety limits, the patient controls administration - Meperidine has a shorter duration of of the opioid analgesic based on the action than morphine, and its amount of pain. potency varies according to the dosage. - To receive the opioid, the patient pushes a button on the PCA device, - Meperidine can be given orally or via which releases a specific dose of IM and IV routes, and it is primarily analgesic (e.g., 1 mg morphine) into effective in GI procedures. the IV line. - During pregnancy, meperidine is - The nurse sets the PCA pump with preferred to morphine because it the opioid analgesic dose prescribed does not diminish uterine by the health care provider by contractions and causes less regulating the time intervals (every neonatal respiratory depression. several minutes) at which the drug can be received. - Meperidine causes less constipation and urinary retention than morphine. - A lockout mechanism on the electronically controlled infusion - When older adults and patients with pump prevents the patient from advanced cancer receive large doses constantly pushing the button and of meperidine, neurotoxicity (e.g., causing a drug overdose. nervousness, tremors, agitation, irritability, seizures) are reported. - The PCA device maintains a near- constant analgesic level, avoiding - Meperidine should not be prescribed episodes of severe pain or for long-term use; the dosage is oversedation. frequently limited to 150 mg/dose for a period no longer than 48 to 72 - It is imperative that the patient, not hours the family or the nurse, control the PCA device to avoid overdosing. PATIENT-CONTROLLED ANALGESIA - Patient-controlled analgesia (PCA) is an alternative route for opioid administration for self-administered pain relief as needed.  PHARMACOLOGY AMPHETAMINES - stimulate the release of the neurotransmitters norepinephrine and dopamine from the brain and sympathetic nervous system (peripheral nerve terminals) and inhibit the reuptake of these transmitters. - Amphetamines ordinarily cause STIMULANTS euphoria and increased alertness, - Numerous drugs can stimulate the but they can also cause insomnia, central nervous system (CNS), which restlessness, tremors, irritability, and involves the brain and spinal cord weight loss. and regulates body functions. - These drugs have a high potential for - Medically approved use of CNS abuse, tolerance, and dependence. stimulants is limited to the treatment of attention-deficit/hyperactivity - Excessive use may lead to psychosis. disorder in children, narcolepsy, and the reversal of respiratory distress. - The half-life of amphetamines varies from 9 to 13 hours. - Amphetamines and THE MAJOR GROUPS OF CNS dextroamphetamine are prescribed STIMULANTS INCLUDE: for narcolepsy and ADHD when amphetamine-like drugs are 1. amphetamines and caffeine, which ineffective. stimulate the cerebral cortex of the brain; AMPHETAMINE-LIKE DRUGS FOR ATTENTION- 2. analeptics and caffeine, which act on the brainstem and medulla to DEFICIT/HYPERACTIVITY DISORDER stimulate respiration AND NARCOLEPSY - Methylphenidate and 3. anorexiants which are thought to dexmethylphenidate, classed as suppress appetite by stimulating the amphetamine-like drugs, are given to satiety center in the hypothalamic increase a child's attention span and and limbic areas of the brain. cognitive performance (e.g., memory, reading) and to decrease impulsiveness, hyperactivity, and restlessness.  PHARMACOLOGY - Methylphenidate is also used to treat narcolepsy. - Amphetamine and amphetamine- like drugs should not be taken in the evening or before bedtime because insomnia may result.