Pharm Exam 4: Antibiotics & Immunity

UNM NMNC 3230: Nursing Pharmacology

Penicillin

ex: amoxicillin (-cillin)

I: Staph, Strep, Enterococcus

• Lots of resistance, allergies, cross-hypersensitivity

MoA: Bactericidal (Interferes with cell wall formation)

ADR: GI upset, rash, yeast infection

Cephalosporins

Ex: Cefazolin (-cef/-ceph)

MoA: Bactericidal (Interferes with cell wall formation)

ADR: Diarrhea

• allergy (PCN too)

Glycopeptides

Ex: Vancomycin

MoA: Bactericidal (Binds to cell wall causing immediate death)

I: Treatment of choice for MRSA (IV)

• Given orally for C. Diff

ADR: Red Man syndrome, Ototoxicity, Nephrotoxicity, thrombophlebitis

• Infuse slowly over 60 minutes or more

Peak + Trough

Tetracyclines

Ex: doxycycline (-cycline)

MoA: Bacteriostatic (Inhibit bacterial protein synthesis)

ADR: Discoloration of permanent teeth, inhibits tooth and skeletal formation in fetus, Photosensitivity, Diarrhea

CI: Allergy, Pregnant women, Children under 8 years, warfarin, other antibiotics, antacids, dairy, iron supplements,tub feeding

On an empty stomach, lots of water

Macrolides

Ex: Azithromycin (-mycin)

MoA: Bacteriostatic, can be bactericidal in high doses to some bacteria

• Bind to bacterial ribosomes and inhibit protein synthesis

ADR: GI upset, transient hearing loss & vertigo, hepatotoxicity, QT prolongation

Drug interactions: Highly protein bound

On empty stomach

Aminoglycosides

Ex: Gentamicin (-mycin/-micin)

MoA: Bactericidal (Bind to ribosomes and prevent protein synthesis)

Once a day dosing 

Work best when combined with other antibiotics

ADR: Nephrotoxicity, Ototoxicity,

Quinolones

Ex: Ciprofloxacin (-flox-)

MoA: Bactericidal (alter bacterial DNA)

ADR: ruptured tendons and tendinitis, Peripheral neuropathy, Seizures, Liver injury, Photosensitivity

IV: Infuse slowly over at least 60 minutes

PO: take antacids, iron & calcium supplements, dairy products 2 hours after or 6 hours before ciprofloxacin

Sulfonamides

Ex: Sulfamethoxazole-Trimethoprim (Sulfa-)

MoA: Bacteriostatic (Inhibit bacterial growth by preventing bacterial folic acid)

CI: Allergy, pregnancy + infants

ADR: Rash + Steven Johnsons syndrome, photosensitivity, Immune mediated reactions in other organs, GI upset and diarrhea, Crystalluria

Urinary Tract Antiseptics

Ex: Nitrofurantoin

MoA: bactericidal or bacteriostatic (only work in urinary tract)

ADR: red/brown discoloration of urine, dizziness, drowsiness, headache, photosensitivity

• hypersensitivity: dyspnea, chest pain, chills & cough, pulmonary fibrosis

Admin: take w/ food to minimize GI distress, do not take with pregnancy

Antibiotic Patient Teaching

Take antibiotics exactly as instructed-DO NOT skip or double up

• Give antibiotics within 30 minutes of time due

• Watch peak and trough

Report any rash or allergic symptoms

Use backup birth control method

Do NOT drink alcohol

• Check renal and hepatic function (liver enzyme)

Cause diarrhea

Isoniazid (INH)

Antimycobacterial

I: given alone for prophylaxis or in combo for treatment of TB

MoA: Bactericidal

ADR: Can be toxic to liver or cause hepatitis, Peripheral neuropathy, Visual disturbances

Supplement vitamin B-6

Treatment is 6-9 months (or longer)

Rifampin

Class: broad spectrum antibiotic

I: TB, Legionnaire’s ds., meningococcal meningitis

MoA: inhibits RNA polymerase, suppresses protein synthesis

ADR: GI Effects, Hepatotoxicity/ Hepatitis (no alcohol), Orange/red discoloration of urine, sweat, saliva, tears, rash, itching, flushing

Drug Interactions:

• other anti-TB drugs- increase hepatotoxicity risk

• monitor LFT’s, s/s hepatic disease

Antifungal Drugs

Ex: Miconazole (topical)

I: Athlete's foot, vaginal yeast infections, other skin infections

MoA: Inhibit fungal growth by affecting fungal cellular metabolism

ADR: itching burning after application

OTC - cream or vaginal suppository (2-4 wks)

Antiviral Drugs

Ex: Acyclovir

I: HSV, varicella (chickenpox), and herpes zoster (shingles)

MoA: inhibits viral replication of DNA

ADR: N/V, GI distress, headache, vertigo, renal toxicity, CNS toxicity

Check BUN/SCr, check patency of IV before infusion, keep client hydrated

Chemotherapy

Chemo drugs kill cells during cellular reproduction → Affects all cells, especially rapidly growing cells

IS POISON

Narrow therapeutic index

ADR:

• CTZ targeted (N/V, constipation, diarrhea

• Hair Loss

• Endothelial lining of mouth (ulcers)

• Myelosuppression (bone marrow)

• Ovaries + Gonad suppression

IV: STOP if infiltration is suspected

Methotrexate (MTX)

Class: Folate antagonist/antimetabolite

I: solid tumors, lymphocytic anemia, non-Hodgkin’s lymphoma, rheumatoid arthritis

MoA: inhibits synthesis of DNA in S phase. Immunosuppressive activity by inhibiting lymphocyte multiplication

ADR: CHEMO + hepatotoxicity + skin reactions

• Pregnancy - Category X

Monitor for nausea → administer antiemetic

Leucovorin - antidote for folic acid antagonists

Cisplatin

MoA: forms cross-links between DNA strands prevents reproduction and stimulates apoptosis

I: metastatic testicular, ovarian cancer, endometrial cancer

ADR: Nephrotoxicity, ototoxicity, severe N/V, Myelosuppression

Doxorubicin

Class: Anthracycline - cytotoxic antibiotic

MoA: distorts normal DNA structure, binds enzyme topoisomerase 2, preventing DNA repair, ultimately leading to cell death

I: acute leukemias, lymphomas, thyroid, breast, ovarian cancer, breast cancer, multiple myeloma

ADR: alopecia, red urine & tears, cardiotoxicity, hepatotoxicity, myelosuppression, N/V

Tamoxifen (Nolvadex, Soltamox)

class: selective estrogen receptor modulator

MoA: blocks estrogen from activating on estrogen + breast cancer cells

ADR: N/V, hot flashes, blurred vision, endometrial hyperplasia, amenorrhea, thrombophlebitis/thromboembolism

• Monitor: bone density and LDL levels

Angiogenesis inhibitors

Stop tumor blood flow

Immunomodulators

Drugs that modify immune response by stimulating or repressing immune function

Monoclonal Antibodies:

“-mab”

Ex: adalimumab

SPECIFIC TARGETED THERAPY

• have the ability to target cancer cells without related toxicities

I: cancer, autoimmune disorders, inflammatory disorders

Synthesized using recombinant DNA technology

Interferon alfa-2A

Enable human cells to stop the replication of viruses or cancer cells

I: chronic hepatitis C, hairy cell leukemia, AIDS related Kaposi sarcoma

ADR: flu-like symptoms, insomnia, depression, tremor, headache

Drugs for HIV-1

Antiretroviral - Goal is to suppress viral replication and decrease “viral load”

• Decrease the viruses, increase the WBCs

• Undetectable doesn’t mean cured

Ex: Zidovudine

Zidovudine

Class: NRTI; antiretroviral drug

MoA: prevents reverse transcriptase from preventing viral DNA synthesis

ADR: bone marrow suppression, N/V, abdominal pain, diarrhea, headache, insomnia, dizziness, myalgia, fever

Drug-drug interactions: sulfamethoxazole/trimethoprim, rifampin