Immune System and Drugs

Immune System

It defends the body against bacteria, viruses, fungi, and parasites by identifying and eliminating them

• Includes white blood cells, lymphatic system, and signaling molecules like cytokines

• The immune system maintains body homeostasis by removing harmful and abnormal cells

Innate Vs. Adaptive Immunity

• Innate immunity

  • offers immediate, non-specific defense using physical barriers and immune cells like macrophages and neutrophils

• Adaptive Immunity

  • Adaptive immunity is specific and relies on lymphocytes, B cells and T cells, that recognize and remember antigens

• Both immunity types protect the body but differ in timing and specificity, crucial for effective vaccines and immunotherapies

Natural Immunity

Innate immunity offers immediate, non-specific defense using physical barriers and immune cells like macrophages and neutrophils

Acquired Immunity

develops after exposure to a foreign antigen

Active Immunity

Immunity generated by the body’s immune system responding to a foreign antigen

Passive Immunity

temporary protection from receiving preformed antibodies instead of producing them internally

Types of Vaccines

Vaccines include live attenuated, inactivated, and subunit types, each inducing immunity differently

Herd Immunity Importance

Immunizations help establish herd immunity, preventing disease outbreaks within communities

Bacteriostatic Vs. Bactericidal

Bacteriostatic:

• Drugs that cause bacterial to stop reproducing

Bactericidal:

• Drugs that kill their target bacteria

Gram-Positive Infections

• Known for its ability to lyse, or breakdown, red blood cells

• Ex) Streptococcus, staphylococcus

Gram-Negative Infections

• Bacteria often grow between aerobic and anaerobic areas

• Ex) E.Coli, N. Meningitides

Broad-Spectrum Antimicrobials Vs. Narrow-Spectrum Antimicrobials

Broad-Spectrum

• Targets a wide variety of bacterial pathogens, including gram-positive and gram-negative species

Narrow-Spectrum

• Targets only specific subsets of bacterial pathogens

In the US each year, how many people are infected with antibiotic resistant infections and how many people die from them?

In the US each year at least 2 million people are infected with antibiotic-resistant infections and more than 23,000 die

Antimicrobial Administration

• Therapeutic levels of medications may require administration intervals throughout day

• Half-life can vary significantly between drugs

• Can impact liver/renal function

Immune System Drug Classes

• Immunosuppressants

• Antimicrobial Drugs

  • Antibiotic Drugs

  • Antivirals

    • Antiherpes

    • Antiinfluenza

    • Antihepatitis

    • Antiretrovirals

  • Antifungals & Antiparasitics

Immunosuppressants

Drugs that suppress the immune system to prevent organ rejection and manage autoimmune conditions

• Includes: Glucocorticoids, Azathioprine, Mycophenolate

Glucocorticoids

Includes Prednisone & Decadron

• MoA: Have anti-inflammatory and immunosuppressive effects

• Indication: Essential in treating inflammatory and autoimmune disorders

• Contraindications:systemic fungal infections and live virus vaccines

• Adverse Effects

  • Weight gain

  • Increased appetite

  • Mood swings

  • Insomnia

  • Fluid retention

  • Elevated blood sugar

  • Long-term use can lead to osteoporosis, high BP, and adrenal insufficiency

• Typically reserved for short-term or last-resort use due

• Taper these drugs

Azathioprine

Immunosuppressant drug, reducing inflammation and preventing tissue damage

• MoA: Inhibits DNA synthesis by disrupting the replication and proliferation of T and B cells

• Indication: Management of rheumatoid arthritis, Prevention of rejection in renal transplant

• Contraindications: Hypersensitivity, Pregnancy and/or breastfeeding

• Interactions: ACE Inhibitors, Warfarin

Adverse Effects of Azathioprine

• Nausea

• Vomiting

• Diarrhea

• Higher risk of infections

• More severe adverse effects include bone marrow suppression, pancreatitis, and liver toxicity

Mycophenolate

Immunosuppressive drug to prevent organ rejection

• MoA: Inhibits the proliferation of T and B immune cells

• Indication: organ transplants to prevent rejection

• Contraindication: Pregnancy

• Adverse Effects:

  • GI disturbances (nausea, diarrhea)

  • Headaches

  • Increased susceptibility to infections

  • Bone marrow suppression

  • Increased risk of birth defects

Nursing Considerations for Immunosuppressants

• Do regular blood tests, such as a complete blood cell count to detect bone marrow suppression or infection

• Check liver function and creatinine levels

• Taper glucocorticoids

• Do not take Mycophenolate if pregnant

Antimicrobial Drugs

• Antibiotics

• Antivirals

  • Antiherpes

  • Antiinfluenza

  • Antihepatitis

  • Antiretrovirals

• Antifungals & Antiparasitics

Antibiotics

• Penicillins

• Beta-Lactamase Inhibitors

• Cephalosporins

• Sulfa Drugs

• Fluoroquinolones

• Macrolides

• Aminoglycosides

• Tetracyclines

• Glycopeptides

Penicillins

1st Antibiotic discovered in the 1920’s

• Are bactericidal

• Kill bacteria by interfering with the synthesis of proteins in cellular walls

• Prototype Drugs: Penicillin, Amoxicillin

• Penicillin and Amoxicillin are similar, however Amoxicillin is considered broad-spectrum and Penicillin is a narrow-spectrum

Amoxicillin

Penicillin Drug

• MoA: Inhibits bacterial cell wall synthesis, leading to bacterial cell lysis

• Indication: Treatment of infections due to susceptible organisms (only beta-lactamase-negative)

• Contraindication: Hypersensitivity, Caution with Renal Impairment

• Interactions: Aminoglycosides and Tetracyclines

Adverse Effects of Penicillins

• Nausea, vomiting, diarrhea

• Monitor for c-diff, candidiasis & hyperkalemia

• Yeast infections

• Anaphylactic Reactions (hypersensitivity)

Nursing Considerations for Penicillins

• Monitor for signs and symptoms of anaphylaxis

• Take the entire prescribed course of the medication to ensure adequate treatment and to reduce the development of antibiotic drug resistance

• Maintain adequate hydration

• Monitor kidney function for renally eliminated medications, such as penicillins, most cephalosporins, vancomycin, aminoglycosides, and particularly fluoroquinolones.

• Monitor for severe or bloody diarrhea and, if ordered, obtain a sample to check for C. difficile

Beta-Lactamase Inhibitors

Beta-lactams are an antibiotic group which contain a beta-lactam ring that is essential for antibacterial activity of antibiotics like penicillin and cephalosporins

• Due to widespread use of antibiotics, bacteria have acquired resistance by developing an enzyme beta-lactamase

• Some antibiotics are combined with beta-lactamase inhibitors to treat resistant bacteria

• Prototype: Amoxicillin-Clavulanate (Augmentin)

Amoxicillin-Clavulanate (Augmentin)

Beta-Lactamase Inhibitor

• MoA: Bind to beta-lactamase enzymes in the bacteria and prevent the breakdown of the beta-lactam ring in the antibiotic molecule

• Indication: Infections caused by PCN-resistant bacteria

Adverse Effects of Beta-Lactamase Inhibitors

• Allergic reactions: Urticaria, pruritus, anaphylaxis

• Superinfections: vaginitis, candidiasis, c-diff infection

• Nausea

• GI upset

• Diarrhea

• Taste disturbance

Cephalosporins

Slightly modified ‘twin’ to penicillins due to their beta-lactam chemical structure

• May have cross-sensitivities in patients with penicillin allergies

• Prototype Drug: Cephalexin

Cephalexin (Keflex)

First generation cephalosporin

• Bactericidal

• Similar to penicillin

• MoA: Inhibits bacterial cell wall synthesis, leading to bacterial cell lysis

• Indication:

  • Skin and skin structure infections

  • Bone and genitourinary infections

  • Otitis media

  • Community-acquired respiratory tract infections

• Contraindication: Hypersensitivity

• Interactions: alcohol, anticoagulants

• Can enter breastmilk

Adverse Effects of Cephalexin

• Nausea, vomiting, diarrhea

• Monitor for c-diff

• Nephrotoxicity

• May elevate INR

Azithromycin & Erythromycin

Macrolides

• Bacteriostatic

• Complex antibacterial broad-spectrum medication

• MoA: Inhibit RNA protein synthesis and suppress reproduction of the bacteria

• Indication: Respiratory infections, otitis media, pelvic inflammatory infections, and chlamydia

• Contraindication: Caution with liver impairment, concurrent use with drugs that inhibit metabolism

Adverse Effects of Azithromycin & Erythromycin

• Monitor for signs of infection

• GI symptoms

• QT Prolongation

• Discontinue with signs of liver damage/jaundice

• Photosensitivity

• Worsening of Myasthenia Gravis

Nursing Considerations for Macrolides

• Use cautiously with liver impairment

• Take with food

• Avoid excessive sunlight and wear protective clothing and use sunscreen when outside

Vancomycin

Glycopeptide

• MoA: Inhibits bacterial cell wall synthesis

• Indication: Serious or severe infections when other antibiotics are ineffective or contraindicated, Active against gram-positive bacteria

• Contraindications: Hypersensitivity, caution with renal issues

• Interactions: Drugs that increase the risk of kidney damage

• completely ineffective against bloodstream pathogens

• commonly used for C-diff

Adverse Effects of Vancomycin

• Nephrotoxicity

• Ototoxicity

• Red-man syndrome

  • when given too quickly intravenously

  • hypotension

  • rash everywhere, burning and itching

• Allergies

Nursing Considerations for Vancomycin

• Obtain cultures before administration

• Trough levels need to be monitored for effective dosing to avoid complications

• C-Diff can occur up to 2 months after therapy ends

Tetracycline, Doxycycline

Tetracycline drugs

• Bacteriostatic, inhibit bacterial growth

• MoA: Penetrate bacterial cell wall and binding to ribosome, inhibiting protein synthesis required to make the cellular wall

• Indication: Numerous gram-positive and gram-negative infections

• Contraindications: Pregnant clients during the second and third trimesters,

• Interactions: multivitamins or calcium-containing products

Adverse Effects of Tetracycline and Doxycycline

• Monitor for signs of infection

• GI symptoms

• C-Diff

• Renal/liver impairment

• Photosensitivity

• Oral candidiasis

• Permanent teeth discoloration if given to children <8

Nursing Considerations for Tetracycline and Doxycycline

• Impede effectiveness of oral contraceptives

• Impaired absorption with use of dairy products

• Avoid excessive sunlight, wear protective clothing and use sunscreen when outside

Levofloxacin

Fluoroquinolone drug

• Broad-spectrum synthetic antibacterial

• MoA: Works by inhibiting the bacterial DNA replication

• Indication: Pneumonia or complicated skin or urinary tract infections

• Contraindications: in children except: complicated UTIs, pyelonephritis, plague, or post-anthrax exposure

• Interactions: multiple QTc-prolonging medications, multivitamins or calcium-containing products

Adverse Effects of Levofloxacin

• Monitor for signs of infection

• Allergies

• GI symptoms

• C-Diff

• Drowsiness

• Photosensitivity

• Rash

• Fainting

• Decreased HR

• Prolonged QT

• Mood changes

• Severe Adverse Effects

  • Tendinitis and tendon rupture

  • Peripheral neuropathy

  • Central nervous system effects

  • Exacerbation of muscle weakness in patients with myasthenia gravis

Nursing Considerations for Levofloxacin

• Dose adjustment for renal or hepatic impairment

• Administer 2 hours before or after meals, antacid, or iron

• Give with plenty of fluids

Sulfamethoxazole-Trimethoprim

Sulfa drugs

• MoA: Bacteriostatic inhibition of growth against wide spectrum gram-positive and gram-negative pathogens

• Indication: UTI’s, Otis media, acute exacerbations of chronic bronchitis, travelers diarrhea

• Contraindication: Hypersensitivity, severe renal or hepatic failure

• Interactions: Caution with oral anti-diabetics, anticoagulant medications

Adverse Effects of Sulfamethoxazole-Trimethoprim

• Monitor for signs of infection

• Allergies

• GI symptoms

• Headache

• Photosensitivity

Nursing Considerations for Sulfamethoxazole-Trimethoprim

• Dose adjustment for renal impairment

• Use cautiously with oral anti-diabetics, may increase hypoglycemic effects

• Use cautiously with anticoagulant medications such as warfarin; may increase risk of bleeding

Gentamicin

Aminoglycoside

• Bactericidal

• Potent broad-spectrum

• MoA: Bind with an area of the ribosome, inhibiting protein synthesis in the cell wall and resulting in bacterial death

• Indication: Severe infections of GI, respiratory, urinary tracts, CNS, bone, skin and soft tissue

• Contraindication: severe renal dysfunction, pregnancy

• Interactions: potent diuretics, other aminoglycosides

Adverse Effects of Gentamicin

• Monitor for signs of infection

• GI symptoms

• Rash

• Ototoxicity

• Nephrotoxicity

• Neurotoxicity

Nursing Considerations for Gentamicin

• Can cause harm to fetus and breastfed infants

• Obtain culture before administering

• Blood sample for peak level should be obtained1 to 2 hours after IM injection; obtain blood for trough level just before next dose

Antivirals

Do not kill offending virus, they work to reduce replication and development of the virus

• Several subclasses:

  • Antiherpes

    • Acyclovir

  • Antiinfluenza

    • Tamiflu

  • Antihepatitis

  • Antiretrovirals

Acyclovir

Antiherpes drug

• MoA: Causes termination of the DNA chain during viral replication process

• Indication: Herpes and varicella infections, Genital herpes, chicken pox, shingles, Epstein-Barr, Cytomegalovirus

• Contraindication: Hypersensitivity, caution with renal impairment

• Interactions: drugs that affect kidney function

• Give with food

Adverse Effects of Acyclovir

• GI Distress

• Renal Impairment

• Decreased seizure threshold

Nursing Considerations for Acyclovir

• Medication compliance

• Can experience fatigue, encourage periods of rest

• Avoid sexual contact while lesions are present

Tamiflu (Oseltamivir)

First-line option for treatment of influenza and is given orally over 5 days

• Adverse Effects: GI discomfort, including nausea, vomiting, and diarrhea.

• Contraindication: hypersensitivity

Antiretrovirals

Drugs that treat infections caused from retroviruses

• MoA: Impede virus replication

• Indication: Treatment of HIV

• Contraindication: severe hepatic or renal impairment, pregnancy/breastfeeding

• Adverse Effects:

  • Severe hepatomegaly

• Stop treatment with pancreatitis

• Use cautiously in renal impairment

Antifungals & Antiparasitics

• Antifungals

  • Work by killing cells of the fungus or inhibiting the reproduction of cells

  • Example: Candida albicans, overgrowth in the mouth produces oral thrush

  • Azoles and polyenes effectively treat fungal infections like candidiasis and aspergillosis by targeting fungal cells

  • Prototype Drugs: Amphotericin B, Fluconazole, Nystatin

• Antiparasitic Agents

  • Antimalarials and anthelmintics combat parasitic infections, essential for managing diseases caused by parasites.

Amphotericin B

Polyene antifungal drug

• broad-spectrum antifungals

• MoA: bind to ergosterol in the fungal cell membrane, leading to membrane breakdown and fungal cell death.

• Indication: trears severe systemic fungal infections

Adverse Effects Amphotericin B

Is very toxic and can cause flulike symptoms during infusion, hypotension, renal toxicity, and electrolyte disturbances

Fluconazole

Azole antifungal

• MoA: Inhibits fungal cytochrome P450 activity, decreasing ergosterol synthesis and inhibiting cell membrane formation

• Indication: Treatment of fungal infections caused by susceptible fungi

• Contraindication: Hypersensitivity, Pregnancy, Coadministration with QT interval–prolonging drugs

Adverse Effects of Fluconazole

• Headache

• Skin rash

• Abdominal pain

• Diarrhea

• Dizziness

• QT interval prolongation

Nystatin

Polyene antifungal

• MoA: ind to ergosterol in the fungal cell membrane, leading to membrane breakdown and fungal cell death.

• Indication: infections such as oropharyngeal candidiasis (thrush).

• Not absorbed systemically when taken orally or topically, therefore, it is ineffective for systemic infections

Nystatin Adverse Effects

• GI Issues

• Skin rash

Nursing Considerations for Antifungal Drugs

• Monitor for signs and symptoms of anaphylaxis

• Advise the client to take the entire prescribed course of the drug to ensure adequate treatment and to reduce the development of drug resistance.

• Instruct the client to maintain adequate hydration; monitor kidney function with renally eliminated medications.

• Ensure that blood samples for any drug levels ordered are obtained at the intended time in order to allow accurate assessments regarding dosage adjustments.

• Monitor the ECG for prolongation of the QTc interval when clients are taking systemically acting agents.

• Monitor liver function tests to assess for liver injury.

• Check a client’s medication list prior to administering a systemic azole antifungal because oral and intravenous azole antifungals inhibit CYP3A4 and can cause many drug interactions.