Naloxegol

MOVANTIK

What it isPeripherally restricted mu antagonist; opioid-induced constipation.

Why this onePEGylation keeps it out of the CNS, so it reverses gut opioid effects without reversing analgesia.

What limits itGI perforation risk, so avoid in known or suspected obstruction. CYP3A4-dependent; take on an empty stomach.

FDA-approved for

FDA dosing	Population	Start	Target	Max
Opioid-induced constipation (chronic non-cancer pain)	Adults	25 mg QD (morning)	25 mg QD	25 mg QD

Renal CLcr <60 mL/min: start 12.5 mg QD, may increase to 25 mg QD if tolerated; no adjustment in mild impairment

Hepatic Mild-moderate: no adjustment; avoid in severe (Child-Pugh C, not evaluated)

If 25 mg not tolerated, reduce to 12.5 mg QD

Take on empty stomach ≥1 h before first meal of day or 2 h after
Discontinue maintenance laxatives before starting; may resume after 3 days if needed
If unable to swallow, tablet may be crushed and mixed in water or given via NG tube
Avoid grapefruit / grapefruit juice
Discontinue if opioid pain medication is discontinued

Known/suspected GI obstruction or at risk of recurrent obstruction (GI perforation risk)
Concomitant strong CYP3A4 inhibitors (may precipitate opioid withdrawal)

Pregnancy May precipitate opioid withdrawal in mother and fetus; human data insufficient

Lactation Breastfeeding not recommended (opioid withdrawal risk in infant)

NO BOXED WARNINGS

Principal riskGI perforation; opioid withdrawal

Cost, est. cash$300–$2,500/month

Generic entry2032 est.

Therapeutic safety burden1 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk1 / 4

Legacy pregnancy categoryC

Defining liabilityDiarrhea, dehydration and electrolyte disturbance, especially with excessive or prolonged use.