Antimicrobial Flashcards
What are the four major classes of antibacterial meds
Inhibitors of bacterial: cell wall synthesis protein synthesis DNA replication metabolic pathways
Antibacterial meds can be administered…
Topically or systematically
E.g. of inhibitors of bacterial cell wall synthesis
Beta-lactams, cephalosporins, carbapenems
E.g. of beta-lactams
Penicillin (amoxicillin, amoxicillin with clavulanic acid, ampicillin, benzathine benzylpenicillin, benzylpenicillin, dicloxacillin, flucloxacillin, phenoxymethylpenicillin)
What do beta-lactams do
Beta-lactam ring essential for antibacterial activity and specific enzymes can disrupt the ring and inactivate their mechanism of action
Beta-lactams are
Safe, effective and widely used
Extensive use of beta lactams leads to…
Resistance in staph
How do beta lactams work
Work by inhibiting synthesis of the bacterial cell wall binding with proteins, producing a defective cell wall which destroyed microorganism
What type of bacteria is penicillin primarily used for
Gram-positive
Who is penicillin contraindicated for
Use in patients with hypersensitivity/allergic reaction to any penicillin preparation and a potential exists for cross-allergenicity with cephalosporins and carbapenems. Penicillin is generally well tolerated
In life-threatening allergic reaction to penicillin…
Cephalosporin and carbapenem shouldn’t be used coz similar to penicillin action
Common AEs of beta-lactams
Diarrhoea, nausea, pain and inflammation at injection site, superinfection with prolonged treatment, allergy
E.g. of carbapenems
Ertapenem, imipenem, meropenem
Mechanism of action of carbapenems
Inhibit synthesis of bacterial cell walls by binding with penicillin-binding proteins
Common AEs of carbapenems
Nausea, vomiting, diarrhoea, headache
Characteristics of carbapenems
Broad-spectrum, bactericidal, beta-lactam
Characteristics of cephalosporins
Widely used and derived from a fungus, broad-spectrum.
Cephalosporins against what kind of bacteria?
Activity against gram positive and negative but more active against negative than penicillin is
E.g. of cephalosporins
Cefaclor, cefalexin, cefalotin, cefazolin, cefepime, cefotaxime, cefoxitin, ceftaroline, ceftazidime, ceftriaxone and cefuroxime.
Clinical uses of cephalosporins
Surgical prophylaxis, treatment of infections of resp tract, urinary tract, skin, soft tissues, bones, joints, CNS, septicaemia
Mechanism of action of cephalosporins
Damage cell wall by binding to penicillin-binding proteins leading to cell lysis and death
Common AEs of cephalosporins
Diarrhoea, nausea, vomiting, rash, headache
Contraindications for cephalosporins:
Previous anaphylactic reaction to penicillin or a cephalosporin allergy
Aminoglycosides characteristics
Widely used for gram negative, bactericidal, similar to penicillin in pharmacologic, antimicrobial and toxiocologic characteristics
How is aminoglycosides administered
Parentally cos poorly absorbed from GI tract
E.g. of aminoglycosides
Amikacin, gentamicin, streptomycin, tobramycin
How do aminoglycosides work
Work by penetrating the cell walls of the bacteria and preventing protein synthesis
Common AEs of aminoglycosides
Nephrotoxicity, ototoxicity, anaphylaxis, bronchospasm, oliguria, peripheral neuropathy
E.g. of inhibitors of bacterial protein synthesis
Aminoglycosides and macrolides
Effects of macrolide
Have immunomodulatory and anti-inflammatory effects
Macrolides have a similar spectrum of antimicrobial activity to…
Benzylpenicillin, can be used for people with penicillin and cephalosporin allergy
E.g. of macrolides
Azithromycin, clarithromycin, erythromycin, roxithromycin
Macrolide properties:
Bactericidal or bacteriostatic depending on dose and bacteria
Common AEs of macrolides
Nausea, vomiting, diarrhoea, abdo pain, cramps, candida infections
E.g. of inhibitors of bacterial metabolic pathways
Sulfonamides
Sulfonamides are bacteriostatic against…
Wide range of Gm + and -, however decreasing in efficacy due to AMR
When can you use sulfonamides
Should only be used after susceptibility is proven by culture and sensitivity testing
E.g. of sulfonamides
Sulfadiazine, sulfisoxazole, trimethoprim-sulfamethoxazole, mafenide, silver sulfadiazine
Common AEs of sulfonamides
Burning, itch, rash, transient leucopoenia
E.g. of inhibitors of bacterial DNA replication
Quinolones/ fluoroquinolones
E.g. of quinolones/ fluoroquinolones
Ciprofloxacin, moxifloxacin, norfloxacin, ofloxacin
Properties of quinolones/ fluoroquinolones
Synthetic bactericidal, active against gram + and –, well absorbed orally
What are quinolones/ fluoroquinolones used for
Used for infections of resp tract, genitourinary tract, GI tract, bone, joints, skin, soft tissues
Mechanism of action of quinolones/ fluoroquinolones?
Interferes with bacterial DNA enzyme synthesis
Common AEs of quinolones/ fluoroquinolones?
Rash, itch, nausea, vomiting, diarrhoea, abdo pain, dyspepsia
What do most antifungals target
Most target fungal cell membrane and disrupt the structure and function of fungal cell components. Can produce potentially serious toxicities and drug interactions
Antifungals can be applied
Superficially or systemically
E.g. of antifungals
Azoles, echinocandins, amphotericin B
E.g. of azoles
Fluconazole, isavuconazole, itraconazole, ketoconazole, miconazole, Posaconazole, voriconazole
How do azoles work
Work by impairing the synthesis of ergosterol in fungal cell membranes causing cell breakdown, cell leakage and cell death
E.g. of echinocandins
Anidulafungin, caspofungin, micafungin
How do echinocandins work
Inhibit 1,3-beta-D-glucan synthase which inhibits synthesis of 1,3-beta-D-glucan in the fungal cell wall and alters cell membrane permeability
Common AEs of echinocandins
Nausea, vomiting, diarrhoea, rash, hypokalaemia
How does amphotericin B work
Works by binding irreversibly to ergosterol in fungal cell membranes causing cell death by altering their permeability and allowing leakage of intracellular components
Common AEs of amphotericin B
Infusion reactions, thrombophlebitis, anaemia, nephrotoxicity, hypoxia, hyperglycaemia, tachycardia, hyponatraemia
What do antiprotozoal drugs do
Either destroy or inhibit protozoa growth and ability to reproduce
What are the two main types of antiprotozoals
Antimalarial and antiprotozoal
What do antimalarials do
Kill or inhibit growth by affecting different stages of the parasitic lifecycle
E.g. of antimalarials
Atovaquone with proguanil (combination is synergistic), clindamycin, doxycycline, hydroxychloroquine
What else can antimalarials be used for
Hydroxychloroquine can be used as an anti-inflammatory
Most common side effects of antimalarials:
Nausea, vomiting, diarrhoea, anorexia, abdo cramps, rash and itch
E.g. of antiprotozoals
Metronidazole and tinidazole
What do metronidazole and tinidazole do
Work by interfering with DNA synthesis
What are metronidazole and tinidazole often used for
In treating non-protozoal infections
Common side effects of metronidazole and tinidazole
Nausea, anorexia, abdo pain, vomiting, diarrhoea
What can and can’t antivirals do
They inhibit viral replication but can’t eliminate virus from host tissue
What are neuraminidase inhibitors used for
In the treatment and prevention of influenza A and B
What do neuraminidase inhibitors do
Reduce virus replication
E.g. of neuraminidase inhibitors
E.g. oseltamivir, peramivir, zanamivir
AEs of neuraminidase inhibitors
Bronchospasm, dyspnoea and allergy
What are the meds for herpes simplex or cytomegalovirus treatment
Acyclovir, famciclovir, ganciclovir, valaciclovir
How do herpes simplex or cytomegalovirus meds work
Work by inhibiting viral DNA polymerase and DNA synthesis
Common side effects of herpes simplex or cytomegalovirus meds
Nausea, vomiting, diarrhoea, hallucinations, headache and encephalopathy
What are the different types of meds for HIV
Antiretrovirals, nucleoside reverse transcriptase inhibitors (NTRI), non-nucleoside reverse transcriptase inhibitors, HIV protease inhibitors, integrase inhibitors
How do antiretrovirals work
Work by stopping the virus replicating in the body to prevent further damage
Antiretrovirals usually require a…
Combination of drugs
NTRI are used in the treatment of
HIV infection or transmission
E.g. of NTRIs
Abacavir, emtricitabine, lamivudine, zidovudine
How do NTRIs work
Work by inhibiting viral reverse transcriptase and viral DNA synthesis
Side effects of NTRIs
Headache, nausea, vomiting, anorexia, myalgia, asymptomatic hyperlactataemia
E.g. of non-NTRIs
Efavirenz, etravirine, nevirapineor, rilpivirine
How does rilpivirine work
By inhibiting HIV-1 reverse transcriptase and thus reducing viral DNA synthesis
Common side effects of rilpivirine
Rash, malaise, nausea, vomiting, elevated liver enzymes, headache, fever
How do HIV protease inhibitors work
By inhibiting HIV-1 and HIV-2 proteases thus preventing virus replication
E.g. of HIV protease inhibitors
Atazanavir, darunavir, fosamprenavir, ritonavir, saquinavir, tipranavir
Side effects of HIV protease inhibitors
Headache, nausea, vomiting, abdo pain, elevated liver enzymes, weight gain, hyperglycaemia, new-onset of or worsening diabetes, hypertriglyceridemia, hypercholesterolaemia
What do integrase inhibitors do
Inhibit HIV integrase and thus stop the insertion of viral DNA into the host DNA
E.g. of integrase inhibitors
Bictegravir, dolutegravir, elivetigravir, raltegavir
Common side effects of integrase inhibitors
Headache, fatigue, nasopharyngitis, increased liver enzymes, increased creatine kinase, rash, nausea
