Chemotherapy PDF

Chemotherapy Anti-infective drugs Anti-infective drugs include: antibacterial, antiviral, antifungal and antiparasitic (antiprotozoal or anthelmintic) agents. Antibacterial Drugs Classification: 1. Cell wall synthesis inhibitors. 2. Protein synthesis inhibitors. 3. Folic acid synthesis inhibitor...

Chemotherapy Anti-infective drugs Anti-infective drugs include: antibacterial, antiviral, antifungal and antiparasitic (antiprotozoal or anthelmintic) agents. Antibacterial Drugs Classification: 1. Cell wall synthesis inhibitors. 2. Protein synthesis inhibitors. 3. Folic acid synthesis inhibitors. 4, Nucleic acid (DNA/RNA) synthesis inhibitors 16 ae es ay % aan. ca FORTUP Examples: Parenteral [cefotaxime 1 gram (cefotax); cefoperazone (cefobid); ceftazidime (fortum); ceftriaxone (rocephin)], Oral cefixime (suprax)] Cefotaxime, ceftriaxone are approved for treatment of meningitis Cefixime can be given orally in respiratory and urinary tract infections. Ceftriaxone is the therapy of choice for all forms of gonorrhea. 4- Fourth-generation Examples: Parenteral Cefepime (maxipime) Cefepime penetrates well into CSF Particularly useful for the empirical treatment of serious infections in hospitalized patients. 22 La 30) Ss & & Th re dat “\ G y e asa saanl LX oo Dy - e 4 @ _ * wv a » Y) a... General adverse effects of cephalosporins: Generally, the cephalosporins have an excellent safety record. However, they may cause: 1. Allergy (ranges from skin rash, anaphylaxis, nephritis, granulocytopenia, hemolytic anemia). There is some cross- antigenicity with penicillins. 2. Local irritation & thrombophelebitis at site of injections 3. Renal toxicity 4.Hypoprothrombinemia and bleeding disorders (with some drugs e.g cefoperazone, cefamandole) (can be prevented by Vitamin K, 10 mg twice weekly). Nursing Implications Review the history of either penicillin or cephalosporine allergy. Be aware regarding the IM or IV preparation (some IM dosage form using local anaethetic Lidocaine that should not be given iV.) When administering a cephalosporin parenterally, the IM injection should be given deeply into a large muscle mass. Oral cephalosporins should be taken with six to eight ounces of water; avoid taking them with acidic fluids as these will destroy the drug. Prolonged use may lead to superinfection, and clinicians should be alert for Clostridium difficile—associated diarrhea in patients who present with persistent diarrhea after use. 23 eRe ese | » > ; © ¢ Patients should be warned to abstain from alcohol during therapy and for the ° Ay first 72 hours after completing therapy, as alcohol in combination with some ~~ 2 cephalosporins can cause a disulfiram-like reaction. “ 2 Fluoroquinolones The fluoroquinolones are bactericidal via their action of interfering with DNA gyrase, which is an enzyme needed to synthesize bacterial DNA. The inability to synthesize DNA kills the bacterial cell. The quinolones/ fluoroquinolones have a very broad spectrum of antibacterial activity. Clinical uses 1. Ciprofloxacin is used for urinary Tract Infections 2. Gastrointestinal Infections caused by shigella, salmonella (e.g. Typhiod fever) 3. Respiratory quinolones [Levofloxacin} used in treatment of Sete diate respiratory Tract Infections int © 500. a 4. Genital, Bone, Joint, and Soft Tissue Infections. a c Adverse effects Meo eee 1. GIT (nausea, vomiting, and diarrhea): the most common side effects. 2. CNS: headache, delerium, hallucination 3. Photosensitivity 4, Abnormal liver function tests 5. Damaging growing cartilage and causing arthropathy (so, it is not routinely recommended in patients below 18 years). However, the arthropathy 1s 24 vrweewFewewewewewrewewrewewewveerewewewwewe#s#see¢?¢ ~ vw VY Vw ww reversible and there is a growing consensus that fluoroquinolones may be used in children in some cases (e.g for pseudomonal infection in patients with cystic fibrosis).. Disturbance in blood glucose level. - Concurrent administration of a fluoroquinolone with any of the following medications decreases absorption of the fluoroquinolones: sucralfate; antacids; calcium, zinc, and iron. Nursing Implications. IV preparations should be given over one hour via a large vein. Any sudden joint pain should be reported, particularly in the area of the Achilles tendon. In 2008 the FDA added a black box warning for fluoroquinolones regarding the potential for tendon rupture (Tanne, 2008), it has been proposed that fluoroquinolones may interact with tenocyte regulatory proteins, leading to tendon damage. Offer small frequent meals to patients with gastrointestinal upset. Inhibitors of protein synthesis Include tetracyclines, aminoglycosides, chloramphenicol, and macrolides All are bacteriostatic, except aminoglycosides which are bactericidal Tetracyclines (e.g. doxycycline) Absorption: Inhibited by dairy foods, calcium, Al and Fe Antagonistic effect with bactericidal-Penicillin Adverse effects: 25 GIT: the most common adverse effect (nausea, vomiting,. A diarrhea) PY re. “2 ¢ Bone and teeth: discoloration, abnormal growth (not | oa ra used in young childrteen and pregnant or nursing mother). ¢ Photosensitivity e Liver: rise in liver enzymes and fatal hepatotoxicity has been reported in Se i \ pregnant women who received high doses of tetracycline and had impaired renal functions. Uses: + ao \ AR 1) H. pylori 2) Brucellosis CTt 3) Chest infections Ly | Macrolides “ 4 e.g.,_ (azithromycin (zithromax), clarithromycin a Antimicrobial activity s = @ Mainly active against gram-positive organisms. be _ m™ Mycoplasma, legionella, Chlamydia trachomatis.. @ H. Pylori (clarithromycin). Mechanism of action M inhibit protein synthesis Clinical uses Q) Erythromycin used in: 1. Chlamydial infections in respiratory tract, eye, genital system. 26 Z - Pertussis. Erythromycin is the drug of choice for treating persons with Bortedella pertussis. 3. Mycoplasma pneumoniae infection. 4. Acne. It is used as an alternative to penicillin in allergic individual with infection caused by Streptococci, or pneumococci. 6. H.pylori @ Adverse Reactions 1- GIT (the most common) @ Anorexia, nausea, vomiting, and diarrhea (due to direct stimulation of gut motility; it acts as motilin receptor agonist) @ /t is the most common reason for discontinuing oral erythromycin 2- Liver Toxicity (the most dangerous) ™ Cholestatic hepatitis (probably due to allergic reaction) Aminoglycosides (e.g., gentamicin, and amikacin) Inhibit protein synthesis Used in treatment of gram negative infections Main adverse effects: Ototoxicty, nephrptoxicity, and neuromuscular blocker Antivirals include: HVC medications, HBV medications, Herpes medications (e.g. cyclovir) Antifungals include: Azoles (e.g. fluconazole,...) 27