General

Pronunciation:
pat-i-sir-an

Trade Name(s)

• Onpattro

Ther. Class.

none assigned

Pharm. Class.

antitransthyretin small interfering rnas

Indications

Treatment of the polyneuropathy of hereditary transthyretin-mediated amyloidosis.

Action

Contains a double-stranded small interfering ribonucleic acid (siRNA) that causes degradation of mutant and wild-type transthyretin (TTR) mRNA. through RNA interference, which results in a reduction of serum TTR protein and TTR protein deposits in tissues.

Therapeutic Effect(s):

Improvement in neuropathy.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Well distributed to tissues.

Metabolism and Excretion: Primarily metabolized by nucleases to nucleotides; <1% excreted in urine as unchanged drug.

Half-life: 3.2 days.

TIME/ACTION PROFILE (serum TTR concentrations)

Contraindication/Precautions

Contraindicated in:

• None.

Use Cautiously in:

• Moderate or severe hepatic impairment
• Severe renal impairment or end-stage renal disease
• OB:   Safety not established in pregnancy;
• Lactation:  Use while breastfeeding only if potential maternal benefit justifies potential risk to infant;
• Pedi:   Safety and effectiveness not established in children.

Adverse Reactions/Side Effects

CV: heart block

Derm: erythema

EENT: blurred vision, dry eyes, vertigo, vitreous floaters

GI: dyspepsia

Metabolic: ↓ serum vitamin A concentrations

MS: arthralgia, muscle spasms

Resp: upper respiratory tract infections, dyspnea

Misc: infusion reactions

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

None reported.

Route/Dosage

IV (Adults ≥100 kg): 30 mg every 3 wk.

IV (Adults <100 kg): 0.3 mg/kg every 3 wk.

Availability

Solution for injection: 2 mg/mL

Assessment

• Monitor for signs and symptoms of infusion-related reactions (flushing, back pain, nausea, abdominal pain, dyspnea, chest pain, rash, headache, increased HR, facial edema, hypotension, syncope) during infusion. May require slowing or interrupting infusion. If infusion is interrupted, infuse at slower rate when resuming.
• Monitor infusion site for signs and symptoms of extravasation (phlebitis or thrombophlebitis, infusion site swelling, dermatitis, cellulitis, erythema, burning sensation, injection site pain). Patisiran is not a vesicant.

Implementation

• Patisiran should be administered by a health care professional.
• Premedicate with dexamethasone 10 mg IV, acetaminophen 500 mg PO, diphenhydramine 50 mg IV, and IV H₂  blocker at least 60 min before start of infusion.
• Intermittent Infusion:  Remove vial from refrigerator and allow to warm to room temperature. Do not shake or vortex. Solution is white to off-white, opalescent, and homogeneous. A white to off-white coating occur on inner surface of vial; does not affect quality. Do not administer solutions that are cloudy, discolored, or contain particulate matter. Withdraw dose from 1 or more vials into single syringe. Filter through a sterile 0.45 micron polyethersulfone (PES) syringe filter into a sterile container. Withdraw required volume of filtered solution. Dilution:  Dilute with 0.9% NaCl for a total volume of 200 mL in a di(2-ethylhexyl)phthalate-free (DEHP-free) infusion bag.Gently invert to mix; do not shake. Discard unused solution. Administer immediately after preparation. Solution is stable for 16 hr at room temperature; do not freeze.
• Rate: Infuse via dedicated DEHP-free line through a 1.2 micron polyethersulfone (PES) in-line infusion filter. Infuse over 80 min via an ambulatory infusion pump, at initial rate of 1 mL/min for first 15 min, then increase to 3 mL/min for rest of infusion. May extend duration if infusion related reactions occur. Monitor possible infiltration; manage suspected extravasation according to local standard practice for non-vesicants. Flush IV set with 0.9% NaCl to ensure that all solution is administered.
• If dose is missed and missed dose is administered within 3 days of missed dose, continue dosing according to schedule. If missed dose is administered >3 days after missed dose, continue dosing every 3 wks thereafter.

Patient/Family Teaching

• Explain purpose of patisiran to patient.
• Advise patient to take supplement of vitamin A at recommended daily allowance and to notify health care professional if symptoms of vitamin A deficiency (night blindness) occur.
• Advise patient to notify health care professional immediately if signs and symptoms of infusion-related reactions occur.
• Rep:  Advise patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding. Encourage pregnant patients to enroll in the pregnancy exposure registry that monitors pregnancy outcomes in women exposed to patisiran during pregnancy by calling 1-877-256-9526 or by contacting alnylampregnancyprogram@iqvia.com.

Evaluation/Desired Outcomes

Improvement in neuropathy and improvement in physical functioning, activities of daily living, and autonomic neuropathy.