Adult Dosing Quick Reference

Fixed adult doses for the drugs most commonly used in retail-clinic visits. Cross-check contraindications and allergies before prescribing.

Pediatric dosing →·Anaphylaxis emergency card →

Search drug or indication

Category

Drug	Indication	Dose	Frequency	Duration	Preg / Lact	Notes
Amoxicillin Antibiotic · 500 mg cap	Strep pharyngitis; dental abscess	500 mg PO BID or 1000 mg PO daily	BID	10 days	P: Compatible. L: Compatible.	First-line for GAS pharyngitis.
Safety, pregnancy/lactation & referral Pregnancy: Compatible. Lactation: Compatible. Contraindications PCN anaphylaxis When to refer / ED Peritonsillar abscess → ED Recurrent GAS → ENT Anaphylaxis emergency card →
Amoxicillin-clavulanate Antibiotic · 875/125 mg tab	Sinusitis, AOM, bite wounds	875/125 mg PO BID	BID	7 days (sinusitis 5–7)	P: Compatible. L: Compatible.	Give with food.
Safety, pregnancy/lactation & referral Pregnancy: Compatible. Lactation: Compatible. Safety Diarrhea common — give with food Contraindications PCN allergy Prior amox-clav hepatitis When to refer / ED Orbital cellulitis → ED Deep hand/face bite → surgery/ED Anaphylaxis emergency card →
Azithromycin (Z-pack) Antibiotic · 250 mg tab	CAP, atypical PNA, PCN-allergic strep	500 mg PO day 1, then 250 mg daily days 2–5	QD	5 days	P: Use with caution. L: Compatible.	Rising GAS resistance.
Safety, pregnancy/lactation & referral Pregnancy: Use with caution. Lactation: Compatible. Safety QT prolongation risk — screen for cardiac history and QT-prolonging meds Contraindications Prior macrolide cholestasis Long-QT syndrome When to refer / ED Hypoxia, sepsis criteria → ED Syncope/palpitations on therapy → ED Anaphylaxis emergency card →
Doxycycline Antibiotic · 100 mg cap	CAP, tick-borne illness, acne, MRSA SSTI	100 mg PO BID	BID	7–14 days (indication-specific)	P: AVOID (fetal tooth/bone effects) unless life-threatening rickettsial illness. L: Short courses (≤3 wk) compatible.	Take with full glass of water; remain upright 30 min.
Safety, pregnancy/lactation & referral Pregnancy: AVOID (fetal tooth/bone effects) unless life-threatening rickettsial illness. Lactation: Short courses (≤3 wk) compatible. Safety Photosensitivity — sunscreen Esophagitis risk — don't lie down for 30 min Contraindications Pregnancy (except suspected rickettsial infection) Age <8 y (except rickettsial) When to refer / ED Suspected sepsis or meningitis → ED Severe rash/blistering → ED Anaphylaxis emergency card →
Cephalexin Antibiotic · 500 mg cap	Skin/soft tissue, strep	500 mg PO QID (or 1 g BID for strep)	QID	7–10 days	P: Compatible. L: Compatible.	No MRSA coverage.
Safety, pregnancy/lactation & referral Pregnancy: Compatible. Lactation: Compatible. Contraindications Cephalosporin anaphylaxis When to refer / ED Abscess >5 cm, facial, or systemic signs → I&D/ED Anaphylaxis emergency card →
TMP-SMX DS Antibiotic · 160/800 mg DS tab	UTI, MRSA SSTI	1 DS tab (160/800 mg) PO BID	BID	3 days (uncomplicated UTI) or 5–10 days (SSTI)	P: AVOID in 1st and 3rd trimesters. L: Compatible after 1 mo if infant healthy.	Encourage fluids.
Safety, pregnancy/lactation & referral Pregnancy: AVOID in 1st and 3rd trimesters. Lactation: Compatible after 1 mo if infant healthy. Safety Rash → stop for any mucosal involvement (SJS/TEN) Hyperkalemia in CKD or with ACE-I/ARB Contraindications Sulfa allergy G6PD deficiency Pregnancy 1st/3rd trimester When to refer / ED Pyelonephritis → ED/IV abx Any blistering rash → ED Anaphylaxis emergency card →
Nitrofurantoin Antibiotic · 100 mg cap (Macrobid)	Uncomplicated cystitis	100 mg PO BID (macrocrystals)	BID	5 days	P: Compatible in 2nd trimester; AVOID at term (>38 wk). L: Compatible after 1 mo.	Cystitis only; avoid CrCl <60.
Safety, pregnancy/lactation & referral Pregnancy: Compatible in 2nd trimester; AVOID at term (>38 wk). Lactation: Compatible after 1 mo. Contraindications CrCl <60 mL/min Suspected pyelonephritis When to refer / ED Flank pain, fever, vomiting → ED Anaphylaxis emergency card →
Ciprofloxacin Antibiotic · 500 mg tab	Complicated UTI, traveler's diarrhea (limited)	500 mg PO BID	BID	7–14 days	P: Avoid unless benefit clearly outweighs risk. L: Compatible short courses.	Reserve — FDA boxed warnings.
Safety, pregnancy/lactation & referral Pregnancy: Avoid unless benefit clearly outweighs risk. Lactation: Compatible short courses. Safety Boxed: tendon rupture, peripheral neuropathy, CNS effects, aortic aneurysm Avoid with corticosteroids or in age >60 (tendon) QT prolongation Contraindications Concurrent tizanidine Myasthenia gravis History of FQ-associated tendon rupture When to refer / ED Sudden tendon pain → stop, orthopedic eval New neuropathy → neurology Aortic dissection sx → ED Anaphylaxis emergency card →
Oseltamivir Antiviral · 75 mg cap	Influenza (start ≤48 h)	75 mg PO BID	BID	5 days	P: Compatible — benefit outweighs risk. L: Compatible.	Prophylaxis is 75 mg daily × 7 d.
Safety, pregnancy/lactation & referral Pregnancy: Compatible — benefit outweighs risk. Lactation: Compatible. Safety N/V — give with food When to refer / ED Hypoxia, dehydration, altered mental status → ED Anaphylaxis emergency card →
Cetirizine Antihistamine · 10 mg tab	Allergic rhinitis, urticaria	10 mg PO daily	QD	—	P: Compatible — preferred. L: Compatible.	Non-sedating (mild sedation ~10%).
Safety, pregnancy/lactation & referral Pregnancy: Compatible — preferred. Lactation: Compatible. When to refer / ED Anaphylaxis → epi + ED Chronic urticaria >6 wk → allergy Anaphylaxis emergency card →
Prednisone Steroid · 20 mg tab	Asthma exacerbation, poison ivy	40–60 mg PO daily	QD	5 days (asthma); 10–14 d taper (severe contact derm)	P: Compatible for short bursts. L: Compatible.	No taper needed for ≤7 d burst.
Safety, pregnancy/lactation & referral Pregnancy: Compatible for short bursts. Lactation: Compatible. Safety Glucose ↑ in diabetics Insomnia, mood changes Give in AM to mimic diurnal rhythm Contraindications Active untreated systemic fungal infection When to refer / ED SpO₂ <92%, silent chest → ED Anaphylaxis-triggered exacerbation → epi + ED Anaphylaxis emergency card →
Ondansetron (ODT) GI · 4 mg or 8 mg ODT	Nausea/vomiting	4–8 mg PO ODT q8h PRN	q8h PRN	—	P: Use if benefits outweigh risks; associated with small cleft-lip risk 1st trimester. L: Compatible.	Max 8 mg per dose PO for QT safety.
Safety, pregnancy/lactation & referral Pregnancy: Use if benefits outweigh risks; associated with small cleft-lip risk 1st trimester. Lactation: Compatible. Safety QT prolongation — avoid with other QT drugs Constipation Contraindications Congenital long-QT When to refer / ED Signs of dehydration → ED for IV fluids Bloody or bilious vomiting → ED Anaphylaxis emergency card →

Amoxicillin

Antibiotic

Strep pharyngitis; dental abscess

Dose: 500 mg PO BID or 1000 mg PO daily

Freq: BID × 10 days

500 mg cap

Preg: Compatible.

Lact: Compatible.

First-line for GAS pharyngitis.

Safety, pregnancy/lactation & referral

Pregnancy: Compatible.

Lactation: Compatible.

Contraindications

PCN anaphylaxis

When to refer / ED

Peritonsillar abscess → ED
Recurrent GAS → ENT

Anaphylaxis emergency card →

Amoxicillin-clavulanate

Antibiotic

Sinusitis, AOM, bite wounds

Dose: 875/125 mg PO BID

Freq: BID × 7 days (sinusitis 5–7)

875/125 mg tab

Preg: Compatible.

Lact: Compatible.

Give with food.

Safety, pregnancy/lactation & referral

Pregnancy: Compatible.

Lactation: Compatible.

Safety

Diarrhea common — give with food

Contraindications

PCN allergy
Prior amox-clav hepatitis

When to refer / ED

Orbital cellulitis → ED
Deep hand/face bite → surgery/ED

Anaphylaxis emergency card →

Azithromycin (Z-pack)

Antibiotic

CAP, atypical PNA, PCN-allergic strep

Dose: 500 mg PO day 1, then 250 mg daily days 2–5

Freq: QD × 5 days

250 mg tab

Preg: Use with caution.

Lact: Compatible.

Rising GAS resistance.

Safety, pregnancy/lactation & referral

Pregnancy: Use with caution.

Lactation: Compatible.

Safety

QT prolongation risk — screen for cardiac history and QT-prolonging meds

Contraindications

Prior macrolide cholestasis
Long-QT syndrome

When to refer / ED

Hypoxia, sepsis criteria → ED
Syncope/palpitations on therapy → ED

Anaphylaxis emergency card →

Doxycycline

Antibiotic

CAP, tick-borne illness, acne, MRSA SSTI

Dose: 100 mg PO BID

Freq: BID × 7–14 days (indication-specific)

100 mg cap

Preg: AVOID (fetal tooth/bone effects) unless life-threatening rickettsial illness.

Lact: Short courses (≤3 wk) compatible.

Take with full glass of water; remain upright 30 min.

Safety, pregnancy/lactation & referral

Pregnancy: AVOID (fetal tooth/bone effects) unless life-threatening rickettsial illness.

Lactation: Short courses (≤3 wk) compatible.

Safety

Photosensitivity — sunscreen
Esophagitis risk — don't lie down for 30 min

Contraindications

Pregnancy (except suspected rickettsial infection)
Age <8 y (except rickettsial)

When to refer / ED

Suspected sepsis or meningitis → ED
Severe rash/blistering → ED

Anaphylaxis emergency card →

Cephalexin

Antibiotic

Skin/soft tissue, strep

Dose: 500 mg PO QID (or 1 g BID for strep)

Freq: QID × 7–10 days

500 mg cap

Preg: Compatible.

Lact: Compatible.

No MRSA coverage.

Safety, pregnancy/lactation & referral

Pregnancy: Compatible.

Lactation: Compatible.

Contraindications

Cephalosporin anaphylaxis

When to refer / ED

Abscess >5 cm, facial, or systemic signs → I&D/ED

Anaphylaxis emergency card →

TMP-SMX DS

Antibiotic

UTI, MRSA SSTI

Dose: 1 DS tab (160/800 mg) PO BID

Freq: BID × 3 days (uncomplicated UTI) or 5–10 days (SSTI)

160/800 mg DS tab

Preg: AVOID in 1st and 3rd trimesters.

Lact: Compatible after 1 mo if infant healthy.

Encourage fluids.

Safety, pregnancy/lactation & referral

Pregnancy: AVOID in 1st and 3rd trimesters.

Lactation: Compatible after 1 mo if infant healthy.

Safety

Rash → stop for any mucosal involvement (SJS/TEN)
Hyperkalemia in CKD or with ACE-I/ARB

Contraindications

Sulfa allergy
G6PD deficiency
Pregnancy 1st/3rd trimester

When to refer / ED

Pyelonephritis → ED/IV abx
Any blistering rash → ED

Anaphylaxis emergency card →

Nitrofurantoin

Antibiotic

Uncomplicated cystitis

Dose: 100 mg PO BID (macrocrystals)

Freq: BID × 5 days

100 mg cap (Macrobid)

Preg: Compatible in 2nd trimester; AVOID at term (>38 wk).

Lact: Compatible after 1 mo.

Cystitis only; avoid CrCl <60.

Safety, pregnancy/lactation & referral

Pregnancy: Compatible in 2nd trimester; AVOID at term (>38 wk).

Lactation: Compatible after 1 mo.

Contraindications

CrCl <60 mL/min
Suspected pyelonephritis

When to refer / ED

Flank pain, fever, vomiting → ED

Anaphylaxis emergency card →

Ciprofloxacin

Antibiotic

Complicated UTI, traveler's diarrhea (limited)

Dose: 500 mg PO BID

Freq: BID × 7–14 days

500 mg tab

Preg: Avoid unless benefit clearly outweighs risk.

Lact: Compatible short courses.

Reserve — FDA boxed warnings.

Safety, pregnancy/lactation & referral

Pregnancy: Avoid unless benefit clearly outweighs risk.

Lactation: Compatible short courses.

Safety

Boxed: tendon rupture, peripheral neuropathy, CNS effects, aortic aneurysm
Avoid with corticosteroids or in age >60 (tendon)
QT prolongation

Contraindications

Concurrent tizanidine
Myasthenia gravis
History of FQ-associated tendon rupture

When to refer / ED

Sudden tendon pain → stop, orthopedic eval
New neuropathy → neurology
Aortic dissection sx → ED

Anaphylaxis emergency card →

Oseltamivir

Antiviral

Influenza (start ≤48 h)

Dose: 75 mg PO BID

Freq: BID × 5 days

75 mg cap

Preg: Compatible — benefit outweighs risk.

Lact: Compatible.

Prophylaxis is 75 mg daily × 7 d.

Safety, pregnancy/lactation & referral

Pregnancy: Compatible — benefit outweighs risk.

Lactation: Compatible.

Safety

N/V — give with food

When to refer / ED

Hypoxia, dehydration, altered mental status → ED

Anaphylaxis emergency card →

Cetirizine

Antihistamine

Allergic rhinitis, urticaria

Dose: 10 mg PO daily

Freq: QD

10 mg tab

Preg: Compatible — preferred.

Lact: Compatible.

Non-sedating (mild sedation ~10%).

Safety, pregnancy/lactation & referral

Pregnancy: Compatible — preferred.

Lactation: Compatible.

When to refer / ED

Anaphylaxis → epi + ED
Chronic urticaria >6 wk → allergy

Anaphylaxis emergency card →

Prednisone

Steroid

Asthma exacerbation, poison ivy

Dose: 40–60 mg PO daily

Freq: QD × 5 days (asthma); 10–14 d taper (severe contact derm)

20 mg tab

Preg: Compatible for short bursts.

Lact: Compatible.

No taper needed for ≤7 d burst.

Safety, pregnancy/lactation & referral

Pregnancy: Compatible for short bursts.

Lactation: Compatible.

Safety

Glucose ↑ in diabetics
Insomnia, mood changes
Give in AM to mimic diurnal rhythm

Contraindications

Active untreated systemic fungal infection

When to refer / ED

SpO₂ <92%, silent chest → ED
Anaphylaxis-triggered exacerbation → epi + ED

Anaphylaxis emergency card →

Ondansetron (ODT)

Nausea/vomiting

Dose: 4–8 mg PO ODT q8h PRN

Freq: q8h PRN

4 mg or 8 mg ODT

Preg: Use if benefits outweigh risks; associated with small cleft-lip risk 1st trimester.

Lact: Compatible.

Max 8 mg per dose PO for QT safety.

Safety, pregnancy/lactation & referral

Pregnancy: Use if benefits outweigh risks; associated with small cleft-lip risk 1st trimester.

Lactation: Compatible.

Safety

QT prolongation — avoid with other QT drugs
Constipation

Contraindications

Congenital long-QT

When to refer / ED

Signs of dehydration → ED for IV fluids
Bloody or bilious vomiting → ED

Anaphylaxis emergency card →

For licensed clinician reference only. This content is a quick-reference aid and is not medical advice. Verify every dose, indication, contraindication, and interaction against current manufacturer labeling and authoritative guidelines (AAP, CDC, IDSA, Sanford Guide, LactMed) before prescribing. The authors and publisher accept no liability for clinical decisions made using this tool.