Azithromycin: Uses, Indications, Dosages, Precautions, contraindications, Side Effects & Interactions

Azithromycin

(a-zith-roe-mye-sin)

Classification and Category
Pharmacotherapeutic: Macrolide
Clinical: Antibiotic

Pregnancy category: B

Zithromax, Zithromax TRIPAK, Zithromax Z-PAK, Zmax

Do not confuse azithromycin with erythromycin, Zithromax with Zinacef

General Information

Azithromycin is an antibiotic medication used for the treatment of a wide variety of bacterial infections. This includes chest infections such as pneumonia, infections of the nose and throat such as sinus infection (sinusitis), skin infections, Lyme disease, and some sexually transmitted infections. This drug will not work for viral infections, such as common cold and flu

Azithromycin can cause severe reactions, such as: antibiotic-associated colitis, other superinfections may effect from altered bacterial balance in Gastrointestinal tract. Acute interstitial nephritis, Cholestatic jaundice, hepatic necrosis, hepatotoxicity, or QT prolongation and potential for severe  arrhythmias occurs rarely

Action

It links to the 50S ribosomal subunits of sensitive bacteria and suppresses protein synthesis, extremely higher spectrum of activity than erythromycin, more effective against gram-negative organisms

Therapeutic Effect

Bacteriostatic against the following sensitive organisms: PO, acute pharyngitis/tonsillitis (group A streptococcal), acute skin/soft tissue infections, the community acquired pneumonia

Availability (Rx)

Ophthalmic Solutions: 1%

Oral Suspension: 100 mg/5 mL, 200 mg/5 mL.

Oral Suspension, Extended-Release

Zmax: 2 g

Tablets: 250 mg, 500 mg, 600 mg. Tri-Pak: 500 mg/3 tablets, Z-Pak: 250 mg/6 tablets

Injection: 500 mg

Uses

• Treatment of mild to moderate infections of pharyngitis, tonsillitis (the upper respiratory tract), acute bacterial exacerbations, COPD, pneumonia (lower respiratory tract ), uncomplicated skin and skin structure infections caused by Moraxella catarrhalis, Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma pneumoniae, Haemophilus influenzae, Clostridium, Legionella pneumophila

• NGU or cervicitis, sexually transmitted diseases due to Chlamydia trachomatis

• In children: acute otitis media (H. influenzae, M. catarrhalis, S. pneumoniae)

Precautions

Pregnancy B, breastfeeding, child, 6 months for otitis media, 2 years for pharyngitis, geriatrics, kidney/ hepatic/heart disease, myasthenia Gravis, tonsillitis, QT prolongation, ulcerative colitis, torsades de pointes, exposure to sunlight, restricting sodium, pseudo-membranous colitis, contact lenses, hypokalemia and hypomagnesaemia

Make sure to tell your doctor if:

• You have liver or kidney problems

• You have arrhythmia

• You have allergic to azithromycin or any NSAID

• You are taking other medicines

Indications and Dosages

 ‣ To treat Most infections 

PO

• Adult: 500 mg on day 1 then 250 mg/day on days 2-5 for a total dose of 1.5 g or 500 mg/day for 3 days

• Child 2-15 yr: 10 mg/kg on day 1 then 5 mg/kg 3 4 days

‣ To treat Respiratory tract, skin, and skin-structure infections

PO

• Adults, Elderly. 500 mg once, then 250 mg/day Throughout 4 days

• Children 6 mo and older. 10 mg/kg once (max 500 mg), then 5 mg/kg/day Throughout 4 days (max 250 mg)

‣ To treat Single-dose treatment of community-acquired pneumonia

PO (Extended-release Suspension only)

• Adults and Children ≥ 34 kg. 2g single dose; give at least 1 h before or 2 h after a meal. May also use for adults (only) for sinusitis

• Children weighing 5 to < 34 kg. 60 mg/kg single dose; give at least 1 h before or 2 h after a meal. See manufacturer-specific dosing table

‣ To treat Acute bacterial exacerbations of COPD

PO

• Adults: 500 mg/day for 3 days  

‣ To treat Mycobacterium avium complex (MAC) 

PO

• Adults, Elderly: 500 mg/day in combination

•  Children: 5 mg/kg/day (max 250 mg) in combination

‣ To Prevention of MAC

PO

• Adults, Elderly: 1200 mg/week alone or in combination with rifabutin

• Children: 5 mg/kg/day (max 250 mg) or 20 mg/kg/wk (max 1200 mg) alone or with rifabutin  

‣ To treat Pelvic inflammatory disease

PO/IV

• Adult: 500 mg IV q24hr 3 2 doses, then 250 mg PO q24hr 3 7-10 days

‣ To treat Gonococcal urethritis

PO

• Adults: 2 g as a single dose, but CDC does not recommend due to severe gastrointestinal distress 

‣ To Treat Cervicitis, chlamydia, chancroid, nongonococcal urethritis, syphilis

PO

• Adult: 1 g single dose

‣ To treat Gonorrhea

PO

• Adult: 2 g single dose

‣ To prevent Mycobacterium avium complex in patients with HIV infection 

PO/IV

• Adults: 1.2 g once weekly, as indicated

 ‣ To treat Acute otitis media

PO

• Child >6 mo: 30 mg/kg as a single dose or 10 mg/kg/day 3 3 days or 10 mg/kg as a single dose on day 1 (max 500 mg/day) then 5 mg/kg on days 2-5 (max 250 mg/day)

‣ To Prevention of acute otitis media

PO

• Child: 10 mg/kg q wk 3 6 mo

‣ To treat Pharyngitis, tonsillitis

PO

• Children older than 2 yr: 12 mg/kg/day (max 500 mg) for 5 days

‣ To treat Chancroid

PO

• Adults, Elderly: 1 g as single dose

• Children: 20 mg/kg as single dose. Max: 1 g

‣ To treat Bacterial conjunctivitis/Ophtalmic

PO

• Adults, Elderly, Children 1 yr and older:1 drop in the affected eye ✖ 2 daily, 8-12 h apart for the first 2 days, then instill 1 drop in the affected eye ✖ 1 daily for the next 5 days  

‣ To treat Usual parenteral dosage (community-acquired pneumonia, PID)

IV

• Adults: 500 mg/day, followed by oral therapy to complete the course of treatment. Generally IV given for at least 2 days

Pharmacokinetics

Rapidly absorbed from the GI tract. Protein binding: 7%-50%. Widely distributed. Eliminated primarily unchanged by biliary excretion. Half-life: 68 h

Implementation

PO route

• Provide adequate intake of fluids (2 L) during diarrhea episodes

• Give with a full glass of water; give susp 1 hr before or 2 hr after meals; tabs may be taken without regard to food; do not give with fruit juices

• Store at room temperature

• Reconstitute 1 g packet for susp with 60 ml water, mix, rinse glass with more water and have patient drink to consume all medication, packets not for pediatric use

• Do not take aluminum/magnesium-containing antacids or food simultaneously with this product

Intermittent IV infusion route

• For Injection, to provide concentration of 100 mg/mL, reconstitute each 500 mg vial with 4.8 mL Sterile Water

• Shake well to ensure dissolution

• Further dilute with 250 or 500 mL 0.9% NaCl or D5W to provide final concentration of 2 mg/mL with 250 mL diluent or 1 mg/mL with 500 mL diluent

• Infuse over 60 min (2 mg/mL). Infuse over 3 hrs (1 mg/mL)

Contraindications

Hypersensitivity to azithromycin or other macrolide antibiotics or history of cholestatic jaundice/hepatic dysfunction related to previous use of azithromycin

Interactions

Individual drugs

Increase: ergot toxicity—ergotamine Increase: Dysrhythmias—pimozide: fatal reaction, do not use concurrently

Increase: effects of oral anticoagulants, digoxin, theophylline, methylPREDNISolone, cycloSPORINE, bromocriptine, disopyramide, triazolam, carBAMazepine, phenytoin, tacrolimus, nelfinavir

Decrease: clearance of triazolam

Decrease: absorption of azithromycin—aluminum, magnesium antacids, separate by ≥2 hr

Drug classifications

• Aluminum/magnesium-including antacids may decrease concentration (give 1 hr before or 2 hrs after antacid)

• May increase levels of amiodarone, cycloSPORINE, dronedarone, thioridazine, toremifene, ziprasidone and QT-prolonging medications
• QUEtiapine may increase concentration

• Anticoagulants (orals): increased effect of oral anticoagulants

Drug/laboratory tests

• Increase: CPK, ALT, AST, bilirubin, BUN, creatinine, alk phos

Drugs/food

• Decrease: absorption—food (susp)

Side effects

• CNS: Aggressiveness, agitation, anxiety, asthenia, nervousness, seizures, dizziness, headache, fatigue, hyperactivity, malaise, paresthesia, somnolence, syncope, vertigo

• CV: Chest pain, edema, hypotension, palpitations, prolonged QT interval, elevated serum CK level, torsades de pointes, ventricular tachycardia

• EENT: Hearing loss, mucocutaneous candidiasis, perversion or loss of taste or smell, tinnitus

• ENDO: Hyperglycemia

• GI: Abdominal pain, nausea, vomiting, anorexia, constipation, diarrhea, dyspepsia, flatulence, elevated liver function test results, cholestatic jaundice, hepatic necrosis or failure, hepatitis, pancreatitis, pseudomembranous colitis

• GU: Acute renal failure, elevated BUN and serum creatinine levels, nephritis, vaginal candidiasis

• HEME: Leukopenia, neutropenia, thrombocytopenia

• MS: Arthralgia

• SKIN: Erythema multiforme, photosensitivity, pruritus, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria

• Other: Allergic reaction, anaphylaxis, angioedema, elevated serum phosphorus

level, hyperkalemia, infusion site reaction (such as pain and redness), new or worsening myasthenia syndrome, superinfection

Nursing considerations

Baseline assessment

• Question for history of allergies to azithromycin, erythromycins and hepatitis

• Assess for infection: Appearance of wound, evidence of fever, WBC count

Intervention/evaluation

• Check for GI discomfort, nausea, vomiting. Monitor daily pattern of bowel

activity and stool consistency

• Monitor LFT, CBC

• Assess for hepatotoxicity: abdominal pain, GI disturbances, malaise, fever

• Be alert for superinfection: fever, vomiting, diarrhea, anal/genital pruritus, oral mucosal changes such as, ulceration, pain, erythema

Equipment must be available for anaphylaxis

• Monitor respiratory status: rate, character, wheezing, tightness in chest; discontinue product if these occur

• ECG monitoring for QT prolongation may be indicated

• Monitor I&O ratio, renal studies; report hematuria, oliguria in renal disease; check urinalysis, protein, blood

• Monitor liver tests: AST, ALT, bilirubin, LDH, alkaline phosphatase; CBC with diff

• Monitor allergies before treatment, reaction of each medication; place allergies on chart, notify all people giving products; skin eruptions, itching

• Assess for serious skin reactions: Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema, discontinue if rash occurs

• Assess for pseudomembranous colitis: blood or pus in diarrhea stool, abdominal pain, fever, fatigue, anorexia; obtain CBC, serum albumin

Evaluation

Positive therapeutic result

• Therapeutic response: C&S negative for infection; decreased signs of infection

• WBC within 5000-10,000/mm3

Patient/family teaching

• Tell patient to take azithromycin capsules 1 hour before or 2 to 3 hours after food

• Instruct patient to take tablets or suspension without regard to food

• Instruct patient to consult prescriber before taking OTC drugs, including antacids

• Tell patient to take azithromycin 1 hour before or 2 to 3 hours after taking antacids

• Instruct patient to report sore throat, black furry tongue, fever, loose foul-smelling stool, vaginal itching, discharge, fatigue; may indicate superinfection

• Instruct patient to Avoid concurrent administration of aluminum- or magnesium-containing antacids

• Instruct patient to notify prescriber of diarrhea stools, dark urine, pale stools, yellow discoloration of eyes or skin, severe abdominal pain; cholestatic jaundice is a severe adverse reaction

• Teach patient to notify prescriber if pregnancy is suspected

• Instruct patient to continue therapy for full length of treatment

• Tell to patient to watch for and immediately report signs of superinfection, such as white patches in the mouth