treprostinil sodium

Action

Dilates pulmonary and systemic arterial vascular beds, reducing right and left ventricular afterload and increasing cardiac output and stroke volume. Also inhibits platelet aggregation.

Availability

Injection: 1 mg/ml, 2.5 mg/ml, 5 mg/ml, 10 mg/ml

Solution for oral inhalation: 2.9-ml ampule containing 1.74 mg treprostinil (0.6 mg/ml)

Indications and dosages

➣ To diminish exercise-induced symptoms of pulmonary artery hypertension (PAH) in patients with NYHA class II-IV symptoms

Adults: Initially, 1.25 ng/kg/minute by continuous subcutaneous infusion; if initial dose isn't tolerated, reduce infusion rate to 0.625 ng/kg/minute. For maintenance, may increase infusion rate in increments of no more than 1.25 ng/kg/minute q week for first 4 weeks, then in increments of no more than 2.5 ng/kg/minute q week, if needed. Maximum dosage is 40 ng/kg/minute.

➣ To treat pulmonary arterial hypertension (PAH) WHO Group 1 to improve exercise ability

Adults: Initially, 3 breaths (18 mcg) oral inhalation solution per treatment session q.i.d. If 3 breaths aren't tolerated, reduce to 1 or 2 breaths and subsequently increase to 3 breaths, as tolerated. For maintenance, increase dose by an additional 3 breaths at approximately 1- to 2-week intervals, if tolerated, until target dose of 9 breaths (54 mcg) is reached per treatment session q.i.d. If adverse effects preclude titration to target dose, continue at highest tolerated dose. If scheduled treatment session is missed or interrupted, resume therapy as soon as possible at usual dose. Maximum recommended dosage is 9 breaths per treatment session q.i.d.

Dosage adjustment

• Hepatic insufficiency

• Concurrent use of CYP2C8 inhibitors or inducers

Contraindications

None

Precautions

Use cautiously in:

• renal disease

• history of hepatic disease

• significant underlying lung disease such as asthma or chronic obstructive pulmonary disease (Tyvaso)

• elderly patients

• pregnant or breastfeeding patients

• children.

Administration

See Give first continuous subcutaneous infusion dose in setting where resuscitation equipment is available and other health care personnel can assist if an emergency arises.

• Administer by continuous subcutaneous infusion through subcutaneous catheter with infusion pump made specifically for subcutaneous infusions.

• Expect to adjust continuous subcutaneous infusion dosage for first 6 to 12 weeks as prescriber balances symptom improvement against adverse reactions.

See Don't stop infusion abruptly (may worsen PAH).

• Use oral inhalation solution only with inhalation system provided.

• Don't mix oral inhalation solution with other drugs.

• Space oral inhalation solution treatment sessions equally during waking hours, approximately 4 hours apart.

Adverse reactions

CNS: dizziness, headache, anxiety, restlessness

CV: vasodilation, edema, hypotension, syncope

EENT: jaw pain, throat irritation, pharyngolaryngeal pain (inhalation solution)

Hematologic: bleeding

Respiratory: cough (inhalation solution)

GI: nausea, vomiting, diarrhea

Skin: rash, pruritus, flushing

Other: infusion site pain or reaction (such as erythema, rash, induration), possible fatal bloodstream infections and sepsis (subcutaneous infusion)

Interactions

Drug-drug. Anticoagulants: increased risk of bleeding

Antihypertensives, diuretics, other vasodilators: increased risk of hypotension

CYP2C8 inhibitors (such as gemfibrozil) or inducers (such as rifampin): decreased treprostinil exposure

Vitamin A: increased risk of bleeding

Drug-herbs. Alfalfa, anise, arnica, astragalus, bilberry, black currant seed oil, bladderwrack, bogbean, boldo (with fenugreek), borage oil, buchu, capsaicin, cat's claw, celery, chaparral, chincona bark, clove oil, dandelion, dong quai, evening primrose oil, fenugreek, feverfew, garlic, ginger, ginkgo, guggul, papaya extract, red clover, rhubarb, safflower oil, skullcap, tan-shen: increased risk of bleeding

Patient monitoring

See Especially after first dose, watch closely for severe vasodilation leading to chest pain and hypotension. These signs and symptoms call for emergency measures.

See Monitor vital signs. Assess carefully for indications of right ventricular failure.

• Assess neurologic status. Institute safety measures as needed to prevent injury.

See Watch for infusion site reaction; be aware that route is associated with risk of bloodstream infections and sepsis, which may be fatal.

Patient teaching

• Tell patient continuous subcutaneous infusion is a long-term measure to control PAH and requires a commitment to maintain infusion system.

• Tell patient to follow instructions for operation of inhalation system and for daily cleaning of device components after last treatment session of day.

• Tell patient not to swallow and to avoid skin or eye contact with oral inhalation solution.

See Instruct patient to immediately report signs and symptoms of infusion site reaction (such as redness, rash, and hardened tissue).

• Teach patient which symptoms reflect underlying disease and which may reflect adverse reactions that he should report.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs and herbs mentioned above.