Clinical beta

FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.

Drug Monograph

Tobramycin

Tobramycin

Aminoglycoside (IV, inhaled)

PseudomonasCFLevelsNephrotoxic

Indication

Pseudomonal bacteremia/pneumonia combo β€’ CF inhaled β€’ UTI adjunct selected

At a glance

INDICATIONS (CORE USE)

Like gentamicin β€” **Pseudomonas synergy** common; inhaled for CF; same toxicity footprint.

ADULT DOSE (STANDARD)

5–7 mg/kg IV q24h extended OR traditional divided β€” pharmacy

MAX DOSE

Level-guided β€” not fixed ceiling

Route

IV, IM, inhaled

PEDIATRIC DOSE

Weight-based per NICU/peds β€” pharmacy

Do not miss

Must-not-miss safety points

Major warning

- Nephrotoxicity + ototoxicity - Levels + renal monitoring - Inhaled: bronchospasm risk β€” pre-bronchodilator per protocol - Pregnancy fetal ototoxicity

Indications

USE IF: Susceptible Pseudomonas / GNR serious infection in combination; CF chronic inhaled therapy. AVOID IF: Gentamicin-equivalent narrower-spectrum option works; significant CKD without tight monitoring.

Primary

  • Pseudomonas infection synergy with anti-pseudomonal beta-lactam
  • Cystic fibrosis airway Pseudomonas (inhaled maintenance / eradication protocols)

Secondary

  • Febrile neutropenia combinations when local formulary prefers tobramycin

Other

  • Ophthalmic topical β€” distinct from systemic

Dosing

STANDARD (ADULT PO)

~5–7 mg/kg IV q24h extended-interval OR divided traditional β€” pharmacy (inhaled CF separate)

ADULT DOSE

IV dosing mirrors gentamicin extended-interval nomograms; inhaled CF doses per pulmonology

PEDIATRIC DOSE

Specialized β€” consult.

MAX DOSE

Trough-driven cessation.

Practical Note

Do not assume tobramycin = gentamicin mg swap without pharmacy β€” nomograms differ slightly.

Warnings

Clinical warnings

  • Vestibular toxicity
  • AKI with vancomycin

Adverse effects

  • nephrotoxicity
  • ototoxicity
  • rash

Contraindications

  • Myasthenia gravis relative

Drug interactions

  • Vancomycin
  • furosemide
  • cisplatin
  • NMB

Special populations

Pediatrics

Weight-based per NICU/peds β€” pharmacy

Pregnancy

Avoid systemic in pregnancy if alternatives; inhaled systemic absorption small but caution.

Lactation

See lactation references and product labeling.

Renal impairment

Same as gentamicin β€” aggressive adjustment. **CrCl scaffold (FMBM β€” titrate to FDA/SFDA label + institutional pharmacy nomogram):** - **CrCl β‰₯50** β†’ extended-interval or traditional q8h per **pharmacy nomogram** - **CrCl 10–50** β†’ prolong interval; **trough before 2nd extended dose** mandatory - **CrCl <10** β†’ **dialysis-dependent** redosing; avoid accumulation (**nephro/oto**); consult pharmacy

Hepatic impairment

No major change.

Elderly

High toxicity risk.

Administration

IV infusion; inhaled after bronchodilator if protocol.

Monitoring

  • Monitor: - Before next extended dose β†’ **trough** (Β± peak per protocol) β†’ rising trough β†’ extend interval / hold - Inpatient β†’ creatinine + urine output **β‰₯2–3Γ—/week**; **daily** if unstable, elderly, or vancomycin co-therapy - Vertigo or acute hearing change β†’ **stop drug** β†’ evaluate **ototoxicity** - PFT / spirometry post first inhaled dose in CF
  • Recheck: - No clinical improvement at 48–72h β†’ reassess diagnosis, resistance, source control, and drug interactions - If targets not met after reassessment of dose, organ function, and interactions β†’ escalate per protocol (DO NOT continue blindly)

Overdose / toxicity

Clinical Picture

**Life-threatening (first):** **AKI / dialysis-requiring nephrotoxicity**; acute **vestibular failure / deafness** (ototoxicity). **Secondary:** electrolyte derangement from renal injury.

Immediate Actions

Stop aminoglycoside β†’ IV fluids if hypovolemic β†’ BMP; **obtain drug level**; hearing/vestibular symptom review

Antidote

No specific antidote; treat complications (e.g. anaphylaxis β†’ epinephrine per ACLS)

Decontamination

Parenteral β€” hold further doses; extended-interval error β†’ level-guided next dose

Escalation

Dialysis-requiring AKI, acute deafness/vestibular failure, severe electrolyte derangement β†’ **ICU** + nephrology/ENT; **hemodialysis removes aminoglycosides** β€” redose per pharmacy after HD

Clinical pearls

Common mistakes, resistance logic, and bedside traps

High-Yield Summary

Gentamicin’s cousin β€” **Pseudomonas/CF** niche. **Same toxicity religion**: trough + creatinine.

Clinical pearls

CF eradication vs chronic suppression β€” different goals. Stewardship: stop IV aminoglycoside early when stable. *Stewardship (all antimicrobials):* Empiric choice β†’ syndrome severity + **local antibiogram**; shortest effective course.

Stewardship & safety

  • Trough
  • Renal
  • CF bronchospasm

Pharmacokinetics

Renal elimination; inhaled deposits airway secretions.

Mechanism of action

Aminoglycoside 30S binding β€” concentration-dependent killing.

Common brand names

Saudi Arabia

Nebcin, Tobramycin

Global

(placeholder β€” verify local formulary)

Common trade names are curated examples only β€” formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.

Country practice notes

  • Empiric choice β†’ tie to syndrome, severity, and local antibiogram β€” not habit.
  • IV β†’ PO step-down when oral bioavailability and susceptibility allow.
  • Do not use antibiotics for uncomplicated viral illness β€” stewardship.

References

Saudi Arabia

  • SFDA (Saudi Food & Drug Authority)
  • Saudi National Formulary / MOH (where available)

International

  • WHO Model List of Essential Medicines (verify current edition)
  • US FDA or EU EMA product information (when national SmPC is unavailable)
  • Sanford Guide
  • IDSA / ESCMID (indication-specific)
  • Local antimicrobial stewardship / hospital formulary
  • FDA / SFDA / regional product labeling
  • Sanford Guide
  • IDSA / ESCMID (indication-specific)
  • Local antimicrobial stewardship / hospital formulary
  • FDA / SFDA / regional product labeling

Do not miss

  • Uncomplicated viral URI/bronchitis β†’ antibiotics rarely indicated
  • Narrow or stop when susceptibilities + clinical stability allow
  • Inhaled bronchospasm first dose.
  • Double nephrotoxin with vanco.
  • Trough
  • Renal
  • CF bronchospasm