Anti-Infectives INFECTION PROCESS: Reservoir Susceptible Host Portal of Entry Portal of Exit Mode of transmission Infection Process Reservoir Description → It is the place or location where the infection agents grow and thrive in order for it to reproduce and grow. • Human • Animals • Environment ❖ Humans − There are diseases that may be transmitted from human-to-human interactions such as Sexually Transmitted Diseases (STD), measles, mumps, streptococcal infections and other respiratory pathogens. − Humans can be asymptomatic but can still transmit pathogens to other humans. They may unconsciously transmit disease and make the other susceptible host vulnerable. − ❖ Zoonosis (Animals) − Infection disease that can be transmitted from vertebrate animals to humans. o Brucellosis (cows and pigs) o Anthrax (sheep) o Plague (rodents) o Trichinellosis/Trichinosis (swine) o Tularemia (rabbits) o Rabies (bats, raccoons, dogs, and other mammals) ❖ Environment − plants, soil, and water are can also inhabited by different infection agents. − Soil: fungal agents − Water: legionnaires disease Infection Process Description → It is the location where the pathogen exits and leaves the host. The exit usually is determined by where the infection is found or localized. Examples: → Tuberculosis – lungs – respiratory tract – coughing − Hepatitis B – liver – penetration of blood, semen and others to another susceptible host by the means of invasive penetration to skin and mucous membrane. Portal of Exit Direct Indirect: Mode of Transmission → Direct contact: skin to skin contact (kissing, sexual intercourse) → Droplet spread: sneezing, coughing, talking Remember! → It is the manner in which the pathogen enters the body. The pathogen must penetrate the body in order to reproduce and infect the body. → It is the place where the pathogen resides and infects Susceptible Host Description Causative Agents BACTERIA → Airborne: carried by dust, suspended in the air → Vehicle borne: food, blood, water → Vector borne: mosquitoes, fleas and ticks → One-celled microorganism that can be only be viewed by the means of microscope. → Has a more simple structure as compared to other types of microorganism which their genetic information is encapsulated in a single DNA loop. → Can found anywhere however, not all bacteria can cause harm to humans. → There are various bacteria living inside the human body such as on the skin and in the gastrointestinal tract GRAM STAINING • • • • • GRAM POSITIVE o o gram stain turns into purple Thick cell wall and outer capsule Types based on SHAPE Cocci: Spherical Spirochetes: Corkscrew Bacilli: Rod Spirilla: Spiral Vibrios: Coma Gram Staining It helps to differentiate types of bacteria depending reaction to gram stain procedure. Also, it helps the physician in choosing compatible and effective antibiotics for the specific bacterial infection. GRAM NEGATIVE o o o gram stain turns into red More complex cell wall, 2 cell membrane, small outer capsule and peptidoglycan layer More difficult to treat due to higher penetration demand to the cell. Example: o Staphylococci o Streptococci o Enterococci Causative Agents VIRUS FUNGI PROTOZOA Location Skin and upper respiratory Throat and nasopharynx Human intestine Examples: o o o o o o o o Bacteroides Escherichia Coli (E.Coli) Klebsiella Pseudomonas Proteus Serratia Salmonella Shigella Location Digestive, respiratory and genital Intestinal tract Intestinal Water, soil, skin, intestines Intestinal tract and decaying matter Water, milk Uncooked meats, poultry, eggs Contaminated food and water Description → These are not cells as compared to bacteria however it infects, penetrate the cell and replicate inside and mature virus particle is called virion. → cannot replicate outside a living host. → These are molds and yeast that is widely circulated into the environment and either saprophytic (nourishment from dead organic matter) or parasitic (nourishment from living matter). They produce spores and disseminated into the environment. → There are normal flora in the body such as skin, mouth, GI tract and vagina. The growth of fungi in the human body is restrained in a stable immune system. They are more complex as compared to bacteria. It has complex cell wall and a compound that makes them harder to penetrate and treat → Fungal infection: “mycoses” → Increases the severity in immunocompromised patients such as HIV patients, patient on an immunosuppressant drug such as organ transplant patients. → These are single celled organisms and the protozoans that lived inside the human body are called parasitic protozoans. → Increases the susceptibility to immunocompromised patients. HOSTS 1) 2) 3) 4) Respiratory Gastrointestinal Skin Integrity Placental Types → Dermatophytes – grow on cool temperature → Dimorphic – outside the human body and in warm temperature Protozoans Infection 1) Malaria 2) Ameobiasis 3) Giardiasis 4) Trichomoniasis 1) 2) 3) 4) Parasitic Diseases Protozoa – Gastrointestinal Tract (GIT) Helminths (worms) – Gastrointestinal Tract (GIT) Scabies – Skin Pediculi (lice) – Skin Antibiotic Therapy o o o o DEFINITIONS Goal: To eradicate the causative agent and return the host’s physiologic functioning. The start of antibiotic therapy should be correlated with clinical assessment Assessment should be done during and after the treatment to evaluate the effect of the antibiotics to the body. The effect is not only limited to desire outcome but also includes its adverse effects, side effects and the recurrence of the infections. Empiric Therapy o o This utilizes the antibiotic regimen that best treats the common cause the infection. This is to initiate an early start in the treatment regimen Culture and Sensitivity o Prior to starting an antibiotic therapy, a specimen culture is done to identify the microorganism involved in the infection and the cultured microorganism is tested for sensitivity and susceptibility to different antibiotics. test usually available in 48 to 72 hours. If the antibiotics were started prior to culture and sensitivity, it will have inaccurate results o o Definitive Therapy o Utilization of the most sensitive antibiotics to treat the infection by the means of culture and sensitivity. − − Narrow Spectrum Few/Limited Organism Recommended antibiotic therapy based on the sensitivity testing. − − Broad Spectrum Wide range of bacteria such as gram negative, gram positive and anaerobic bacteria. Consistent use can lead to antibiotic resistance. Antibiotic Resistance o o When the bacteria continuously grow and unable to be eradicated by the drugs intended for them. Accelerated by the means of overusing and misusing antibiotics and because of poor infection control management. Prophylactic Antibiotic Therapy o treatment is being done when the patient will undergo a procedure that is high likely to encounter microbial contamination either during or after the procedure. This will reduce the risk of having an infection. Usually given 30 – 60 minutes prior to incision time. Superinfection o o o Occurs when the normal flora on the body is completely eradicated by the antibiotic therapy. These normal floras serve as a protection to the body, once eliminated, other microorganism will attack the body. Other event may arise from a secondary infection aside from the primary infection because of the weakening of the immune system. Remember! o Common adverse effect of antibiotics is DIARRHEA! Dosage o May be increase for more resistant microorganisms such as Pseudomonas, however, it may also be decrease if there are renal, hepatic or other organ dysfunctions. Route of Administration and Duration o o Mostly are administered via oral (per orem/PO) or Intravenous (IV). Acute infection usually last for 7 to 10 days. T y p e s o f a n t I b I o t I c s Sulfonamides ACTION TYPES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION − − − − − − − − − − − − − − − − − − − − − − − − − − − − Inhibit the growth of the bacteria (Bacteriostatic) Prevent synthesis of folic acid. Effective to those bacteria that synthesis their own folic acid. Combined with Trimethoprim that also prevents folic acid synthesis. These are metabolized in the liver and excreted by the kidneys. Trimethoprim And Sulfamethoxazole (Bactrim) Sulfadiazine (Silvadene) Sulfasalazine (Azulfidine Broad-spectrum Urinary tract infections (UTI) Opportunistic infection of HIV (Pneumonia Drug allergy with sulfonamides and sulfonylureas (drugs containing sulfur) Pregnant women Infants less than 2 months Allergic reaction Photosensitivity Nausea and vomiting Steven-Johnson syndrome Agranulocytosis: instruct if there is a sore throat or fever ↑ the hypoglycemic effect of sulfonylureas. ↑effect of phenytoin and warfarin. ↓ the effectiveness of oral contraceptive Nephrotoxic: ↓of dose with renal impairment Hepatotoxic: ↓of dose with liver impairment Teratogenic Educate: urine may turn into red or dark brown. ↑oral fluid intake to prevent renal damage. (2000ml/day Wear protective clothing and avoid excessive sunlight. Withhold if rash is noted and inform the doctor. Take oral form with food to reduce GIT effects. T y p e s o f a n t I b I o t I c s Β-Lactam o Derive from the beta lactam ring of their chemical structure. The beta-lactam ring is essential for antibacterial activity. o However, there are several microorganisms that have beta-lactamase enzymes that disrupt the betalactam ring which makes them inactivated. o Inhibit cell wall synthesis by binding to proteins (penicillin-binding proteins) in bacterial cell wall. As a result, the cell wall becomes defective and intracellular content leaks out and destroying the microorganism. CLASSIFICATION Penicilin − ACTION − TYPES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION − − − − − − − − − − − − − − − − − − Classification: 1) Penicillins 2) Cephalosporins 3) Carbapenems 4) Monobactams Bactericidal; the penicillin molecules go inside the bacterial cell wall by the means of binding to the bacteria’s receptor site (penicillinbinding proteins PBP). Once the penicillin is inside, it interferes with the cell wall synthesis and destroys the bacteria by the means of lysis. Mainly absorbed at the duodenum and upper jejunum of the small intestines. Natural Penicillin Penicillin G, Penicillin V Gram Positive Penicillin – resistant drugs Cloxacillin, Dicloxacillin, Oxacilin MRSA Aminopenicillin Amoxicillin, Ampicillin Broad Spectrum Extended Spectrum Drugs Piperacillin, Ticarcillin, Broad Spectrum Piperacillin/Tazobactam Gram positive bacteria Streptococcus, Enterococcus and Staphylococcus Infections. Rheumatic Fever MRSA Drug allergy Relatively safe drug Hypersensitivity/ Anaphylactic reactions Lethargy, Hallucinations DIARRHEA: may cause pseudomembranous colitis (C. Difficile) Probenecid: ↑plasma concentration of penicillin, thus increasing its duration ↑ Methotrexate toxicity Neomycin ↓ absorption of penicillin Aminoglycosides ↑ the bactericidal activity and effectiveness. May increase the bleeding time by ↓ vitamin K. Can be IM if PO is inconvenient or questions the compliance. Monitor for any allergic reactions. WOF: bleeding, monitor bleeding parameters. Give IM dose into the large muscle group. Limit it to 2g per injection − − If given via IV, do not mix with other drugs Should be given on empty stomach, at least 1 hour prior or 2 hours after meal to enhance absorption CLASSIFICATION Cephalosporin − ACTION TYPES (GENERATION) INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION Bactericidal; binding to the bacteria’s receptor site (penicillin-binding proteins PBP). It interferes with the cell wall synthesis, thus penetrate the wall and let the natural defenses destroy the bacteria. − Commonly administered parentally because of the poor absorption in the GIT − Excreted via kidney − Cefoperazone and Ceftriaxone excreted in feces via bile. IV PO 1st gen. Cefazolin, Cephradine Cefadroxil, Cephalexin, Cephradine 2nd gen. Cefoxitin, Cefuroxime, Cefotetan Cefaclor, Cefuroxime axetil, Cefprozil 3rd gen Cefotaxime, Ceftizoxime, Ceftriaxone, Cefpodoxime, Ceftibuten, Cefdinir Ceftazidime 4th gen. Cefepime 5th gen. Cefepime − − Drug allergy − − − − Confusion/Seizures Bleeding – Cefotetan and Ceftriaxone ↑the risk of bleeding. Hives/Rashes Alcohol (Ethanol) intake – acute alcohol intolerance (Disulfiram like reaction) – Hypotension, stomach cramps, nausea and vomiting Probenecid – ↑effective of drug Oral Contraceptives – ↓ its effectiveness Cross sensitivity – If allergic to Penicillin, may also have an allergy to Cephalosporin. Monitor for any allergic reactions. Administer to IM large muscle mass Do not add with other drugs when administering. Monitor for Kidney function such as Creatinine and BUN – Nephrotoxic Increase fluid retention with sodium salts. Take oral form with food Prevent alcohol consumption with cephalosporin treatment. Eat yogurt to prevent intestinal superinfection related to drug effect. Limit intake of alcohol because of disulfiram like effect. − − − − − − − − − − − − CLASSIFICATION ACTION TYPES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION Carbapenems − − − − − − − − − − − − − Bactericidal; inhibits the cell wall synthesis. Broadest antibacterial action of any antibiotics to date Imipenem with Cilastatin – excreted in the urine o Cilastatin prevents the rapid breakdown of Imipenem Ertapenem – completely absorbed via IV. Metabolized by hydrolysis and excreted in urine Imipenem – cilastatin sodium (Combination Drug) Meropenem Ertapenem Doripenem Broad Spectrum (E. Coli, Enterobacter/ Klebsiella/ Serratia/ Pseudomonas) Streptococcus, Staphylococcus aureus and epidermins Body cavity and connective tissue infections Bacterial meningitis, UTI, Pneumonia, Endocarditis and intra-abdominal infections Drug allergy − − − − − − − − − − Hypersensitivity/ Anaphylactic reactions Nausea and Vomiting Seizures – reason why carbapenems are not used as first line drug therapy Probenecid + Imipenem – Cilastatin: ↑drug concentration Probenecid + Meropenem or Ertapenem: ↑toxicity level Imipenem + Cilastatin and Aminoglycosides: fights E. faecalis Monitor for any allergic reactions. Dilute the medication and infuse for over 40 to 60 minutes If seizure develops and persist despite using anticonvulsants, refer to the doctor. Watch out for impaired renal function, monitor Creatinine and BUN levels. CLASSIFICATION ACTION EXAMPLE INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS Monobactams − − − − Bactericidal; inhibits the cell wall synthesis and inhibits cell wall division and promotes lysis. Aztreonam is rapidly and completely absorbed and widely distributed. Excreted in urine. Aztreonam − − − − − Gram Negative Pseudomonas, E. Coli, Enterobacter, Klebsiella pneumonia, H. Influezae Complicated and uncomplicated UTI septicemia, Lower respiratory tract infection, intra-abdominal infections, gynecologic infections Drug allergy − − − − − − − Hypersensitivity/ Anaphylactic reactions Nausea and Vomiting Hypotension ↑ level in liver enzymes Ventricular Arrhythmias Probenecid: increase serum levels of aztreonam. Simultaneous with beta lactamase production use is not recommended − − − − − Used when patient is allergic to penicillin. Only in IV form. Monitor for any allergic reactions. Inject IV dose slowly for over 3 – 5 minutes. Give IV infusion for over 20 minutes to 1 hour DRUG INTERACTION NURSING ACTION T y p e s o f a n t I b I o t I c s Macrolides ACTION TYPES/EXAMPLES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION − − − − − − − − − − − − − − Bacteriostatic; inhibit RNA synthesis by entering the microbial cell and attaches to 50s ribosomes It is absorbed in the duodenum; thus, it must be enteric coated to prevent destruction by gastric acids. Erythromycin Ehtylsuccinate Erythromycin Stearate Erythromycin Lactobionate Azithromycin Clarithromycin Fidaxomicin Gram Negative Streptococcus pyogens (group A Beta-hemolytics Streptococcus) Mycoplasma pneumoniae infections/Pneumonia Chlamydia, Gonorrhea, Syphillis Clarithromycin combined with antacids to treat Helicobacter Pylori (Duodenal Ulcer) Drug allergy − − − − − Epigastric distress, Nausea and Vomiting Diarrhea Eosinophilia Palpitations/Chest pains Macrolides can increase theophylline, carbamazepine, cyclosporine, digoxin, warfarin levels; however a lower incidence with Azithromycin because of minimal effects on the cytochrome P-450 enzymes. Check the level of toxicity of the drugs. ↓ effectiveness of oral contraceptives. Used when a history of allergy with Beta Lactam Antibiotics Erythromycin: Metabolized in liver and excreted in bile. Crosses the placental barrier and via breast milk. Azithromycin and Clarithromycin are rapidly absorbed in GIT. Lower incidence of GIT complications Monitor for any allergic reactions. Give oral form with empty stomach, 1 hour or 2 hours after meal. Monitor hepatic functions such as ALT, AST and bilirubin levels. Coated tablets should be taken with meals. Prevent drinking it with juices. − − − − − − − − − T y p e s o f a n t I b I o t I c s Ketolides ACTION − − − − Bacteriostatic; inhibit RNA synthesis Metabolized by the liver. Better acid stability and wider coverage of antibacterial properties. Telithromycin (Keteck) − − − − − − − − − − Gram Positive MRSA Community-Acquired Pneumonia Drug allergy With known cardiac disease Epigastric distress, Nausea and Vomiting Diarrhea Eosinophilia Palpitations/Chest pains Telithromycin + colchicine with renal or hepatic impairment may cause colchicine toxicity − − − − Monitor for any allergic reactions. Watch out for elevated liver enzymes Watch out for cardiac event Hepatotoxic TYPES/EXAMPLES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION T y p e s o f a n t I b I o t I c s Tetracycline − − Bacteriostatic; inhibit RNA synthesis Penetrates bacterial cell wall by energydependent process. It also binds to the 50S subunits and shuts down bacteria’s essential functions by inhibiting bacterial protein synthesis − Absorbed in the duodenum when taken orally. − Excreted by the kidneys − Has the capability to bind to divalent (Ca2+ and Mg 2+) and trivalent (Al3+) metallic compounds, hence, milk, antacids or iron salts lower the oral absorption. Natural Tetracycline Semisynthetic Tetracycline TYPES/EXAMPLES Demeclocycline Doxycycline Oxytetracycline Minocycline Tetracycline − Broad Spectrum INDICATION − Chlamydia − Mycoplasma − Rickettsia/Q fever/Rocky Mountain spotted fever − Protozoa − Demeclocycline: used to treat pleural and pericardial effusion and syndrome of inappropriate secretion of Anti Diuretic Hormone (SIADH) − Tetracycline + Streptomycin: drug of choice brucellosis. − Low doses of tetracycline are used to treat acne CONTRAINDICATION − Drug allergy − Renal failure − Avoid w/ pregnant & breast feeding − Avoid children less than 8 yrs. Old: cause tooth discoloration SIDE/ADVERSE EFFECTS − Discoloration of permanent teeth and tooth enamel hypoplasia − Retard fetal skeletal development if taken during pregnancy − Nephrotoxic/Hepatotoxic − Photosensitive DRUG INTERACTION − Reduces the effectiveness of hormonal contraceptives. − ↓ the bactericidal action of penicillin − ↓ effectiveness if combined with: antacids, antidiarrheal drugs, dairy products and iron supplements. − ↑ the effects of anticoagulation NURSING ACTION − Avoid using it on pregnant women. − Because tetracycline binds to calcium, it prevents the normal bone growth development and enamel hypoplasia. − Monitor for any allergic reactions. ACTION − − − − − − − If being used for large doses, watch out for superinfections. Avoid direct exposure to sunlight and tanning beds Advice to avoid alcohol as it decreases the effectiveness of the drug. Avoid milk or dairy products with tetracycline. Give on an empty stomach for maximum absorption. Do not give 1 hour prior to bedtime to prevent esophageal reflux. If with antacids, wait at least 3 hours before giving antacids T y p e s o f a n t I b I o t I c s Aminoglycosides − − − − − − − Bactericidal; binds to bacteria’s 30S subunits and interrupting protein synthesis. Inactive against anaerobic bacteria. Synergistic effect: combination of 2 antibiotics Post Antibiotic Effect (PAE): continued bacterial growth suppression after short term antibiotic treatment Usually administered via parenterally because poorly absorbed from the GIT. After IV or IM, it rapidly and completely being absorbed by the body. It reaches peak effects in 30 – 90 minutes Therapeutic Level: below 1mcg/ml – therapeutic goal more than 2 mcg/ml – risk for ototoxicity and nephrotoxicity Natural Semisynthetic Tetracycline TYPES/EXAMPLES Gentamicin Natural Amikacin Netilmicin Kanamycin Neomycin Paromycin Streptomycin Tobramycin − Gram Negative INDICATION − Serious nosocomial infections − GIT or GUT surgical procedure prophylaxis − Peritonitis, Pneumonia − UTI − CNS infections: Meningitis − Neomycin: in hepatic failure, it can reduce ammonia producing bacteria and improving neurologic function. CONTRAINDICATION − Drug allergy − Avoid w/ pregnant & breast feeding − Avoid children less than 8 yrs. Old: cause tooth discoloration SIDE/ADVERSE EFFECTS − Neuromuscular reactions – weakens respiratory muscles − Ototoxicity − Nephrotoxicity DRUG INTERACTION − Combination with penicillin to treat gram positive organism − If administered with neuromuscular blockers, increased muscle relaxation and respiratory distress − Don’t give with other nephrotoxic drugs. − Loop diuretics increase the risk of ototoxicity. − Warfarin effects are potentiated with aminoglycosides. ACTION NURSING ACTION − − − Do not mix with other IV infusions. Hold other drugs if need to be given. IM Administration: Give at large mass; Apply ice pack to relieve pain I.V. Administration: Rapid IV push may cause neuromuscular blockade; Dilute antibiotic and infuse for 30 – 60 minutes T y p e s o f a n t I b I o t I c s Fluroquinolones ACTION TYPES/EXAMPLES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − Bactericidal ; interrupt DNA synthesis by inhibiting DNA gyrase; therefore, bacteria cannot reproduce Metabolized by the liver. Oral form absorbed well Metabolized in the liver and excreted by the kidney Ciprofloxacin Levofloxacin Moxifloxacin HCL Norfloxacin Ofloxacin Gemifloxacin Broad spectrum Urinary Tract Infections (UTI) Upper respiratory tract infections/Pnemonia STD/Gonorrhea Cirpofloxacin: Drug of choice for anthrax infectio Drug allergy Children less than 18 years old Cardiac effect that prolongs QT interval Ruptured tendons and tendinitis Nausea and vomiting, diarrhea Abdominal pain CNS Toxicity: Dizziness, lightheadedness, visual disturbances Antacids + Quinolones = reduced absorption Calcium and magnesium drug or compound should be taken separately with quinolones for 1 hour. It decreases the absorption of fluoroquinolones Not recommended for prepubescent children because it affect the cartilage development. Stop breast feeding during treatment Monitor for drug allergy Avoid direct sunlight. Use sunscreen when going outside. Report for any pain at tendons. Oral forms may be given 2 hours before or after meal (not with meals) After 6 hours after taking antacids, sucralfate and iron containing drugs. − − − Dilute drug for IV use and infuse slowly. Increase oral fluid intake to prevent crystal formation (crystalluria). Avoid performing alert-requiring activities such as driving. It may cause dizziness, light headedness and visual disturbances T y p e s o f a n t I b I o t I c s Glycopeptides ACTION − − − Bactericidal; bacterial wall synthesis which damages bacterial plasma membrane. Poorly absorbed by the GIT; preferably via IV − − − − − − − − − − − − − − − − Gram Positive Drug of choice for MRSA infections Oral form: treat Pseudomonas colitis Drug allergy TYPES/EXAMPLES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION Red Man Syndrome Red man syndrome : flushing, itching of the head, face, neck and upper trunk area. Severe Hypotension: Usually due to rapid IV infusion of the drug Vancomycin + Aminoglycosides = Treatment of choice for E. faecalis (endocarditis) Vancomycin + Aminoglycosides/Amphotericin B/bacitracin/cisplatin = ↑nephrotoxicity Monitor for drug allergy Assess kidney function such as Creatinine and BUN. Administer IV form slowly for over 60 minutes. Increase fluid intake Cautious w/ renal dysfunctions (Nephrotoxicity) Caution w/ hearing dysfunctions (Oxotoxicity) Both can be induced if drug’s blood levels are too high ANTI - VIRALS • Viruses enter the body by the means of inhalation (respiratory), ingestion (GIT), placenta (mother and child) or by the means of injection of virus to the system by sexual contact, parenteral treatment such as blood transfusions and syringes. Common Viral Illnesses: • Smallpox • Adenoviruses (sore throat and conjunctivitis) • Retroviruses (Human Immunodeficiency virus (HIV) – AIDS) • Herpesviruses (herpes) • Hepadnaviruses (Hepatitis) • Rotaviruses (Gastroenteritis) • Coronavirus (respiratory infections → Antiviral drugs eliminate viruses by the means of either promoting the destruction of virions or inhibiting their ability to multiply. It cannot be completely eliminating the virus from its host. However, the body of the patient will be able to recover and destroy the viruses by eliminating the replication of the virus by their own defense mechanism. → Immunoglobulins are antibodies being administered to the patient and attacks and destroys viruses. → Acute viral infections are more difficult to manage as compared to bacteria due to the process of viral replication, thus, the antiviral drugs must go inside the host’s cell in order to promote virus destruction. → To fully recover from the viral infection, the antiviral drugs and immune system must work together to fully eradicate the virus living inside the cell Virus Replication Cycle: 1) Attachment: viral protein attached to the cell wall of the host’s cell via the means of receptors 2) Penetration: when attached to the cell, it produces distortion in the viral capsule and cell wall that makes the fuse together and makes the DNA viruses enter the receptor mediated endocytosis. 3) Uncoating – the virus uncoils and releases its nucleic acid inside the normal cell. 4) Replication – promotes de novo synthesis of viral proteins and genome by using the cell’s DNA and RNA to create a virion. 5) Assembly – after the replication, the new viruses that are now called virion, created are gathered and ready for release from the cell. This is called maturation 6) Virion release – the method can be either lysis or budding. Lysis is cell death of the infected host cell and these viruses are called cytolytic. Budding is a method that the virions are released from the cell and does not promote cell death Remember! HSV and VZV antiviral medications does not cure the situation, however it promotes remission and reduces the duration of the infections INDICATION Herpes Simplex 1 and 2 Varicella Zoster Virus Cytomegalovirus (CMV) DRUGS Acyclovir, Famciclovir, Penciclovir Valacyclovir Cidofovir, Ganciclovir, FOSCARNET, Fomivirsen, Trifluridine Influenza A Influenza A and B Amantidine, Rimantadine Zanamivir, Oseltamivir Table 10.1 Antivirals (Non-retrovirals) Influenza A & Syncytial Virus Drugs ACTION − − Blocks the viral replication by preventing the shedding of viral and coat and entry of virus into the cell. Oral administration is well absorbed in the GIT and excreted in the urine. − Flu − − − − Drug allergy Lactating women and children less than 1 year old Nephrotoxic Heart Failure − − − − − − − − − − − − − − − Insomnia Nervousness Lightheadedness, blurring of vision Anorexia Orthostatic Hypotension Anticholinergics – increase anticholinergic like effects CNS stimulants – increases CNS stimulant effects No live vaccines for 2 weeks prior and 48 hours after treatment. Oseltamivir Only antiviral agent that is effective against H1N1 and Avian Flu Indicated for uncomplicated Influenza A and B Amantidine – effective prophylactically and therapeutically against influenza A. However, does not treat the flu. Ribavirin – indicated for Respiratory Syncytial Virus (RSV). Teratogenic even with male sexual partners. Facilitate early administration after the exposure of the virus Administer flu vaccines TYPES/EXAMPLES INDICATION CONTRAINDICATION SIDE/ADVERSE EFFECTS DRUG INTERACTION NURSING ACTION
