cysteamine

Derm: ERYTHEMA MULTIFORME, rash, striae, TOXIC EPIDERMAL NECROLYSIS, urticaria

EENT: hearing loss, papilledema

GI: ↓appetite, diarrhea, vomiting, GI bleeding, GI ulcers, abdominal pain, bad breath, constipation, dyspepsia, fibrosing colonopathy, nausea

Hemat: anemia, leukopenia

MS: fractures, leg pain, osteopenia, tremor

Neuro: lethargy, ataxia, confusion, depression, dizziness, encephalopathy, hallucinations, headache, intracranial hypertension, nightmares, SEIZURES, somnolence

Misc: fever

Interactions ⬆ ⬇

Drug-drug:

Medications that ↑ gastric pH including proton pump inhibitors, H2 receptor antagonists, antacids (including those that contain carbonate and bicarbonate), may cause premature release of cysteamine and ↑ WBC cystine concentrations; need to closely monitor WBC cystine concentrations during concomitant use; administer cysteamine ≥1 hr before or after medications containing bicarbonate or carbonate

Availability ⬆ ⬇

Delayed-release capsules (Procysbi): 25 mg; 75 mg
Delayed-release granules (Procysbi): 75 mg/pkt; 300 mg/pkt
Immediate-release capsules (Cystagon): 50 mg; 150 mg

Route/Dosage ⬆ ⬇

Cystagon

PO (Adults and Children >12 yr and >110 lb): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ gradually over 4–6 wk to maintenance dose. Maintenance dose: 500 mg 4 times daily.
PO (Children <12 yr): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ gradually over 4–6 wk to maintenance dose. Maintenance dose: 1.3 g/m²/day or 60 mg/kg/day in 4 divided doses.

Procysbi

PO (Adults and Children ≥1 yr and ≥51 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 1000 mg every 12 hr.
PO (Adults and Children ≥1 yr and 41–50 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 900 mg every 12 hr.
PO (Adults and Children ≥1 yr and 31–40 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 800 mg every 12 hr.
PO (Adults and Children ≥1 yr and 26–30 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 700 mg every 12 hr.
PO (Adults and Children ≥1 yr and 21–25 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 600 mg every 12 hr.
PO (Adults and Children ≥1 yr and 16–20 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 500 mg every 12 hr.
PO (Adults and Children ≥1 yr and 11–15 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 400 mg every 12 hr.
PO (Adults and Children ≥1 yr and 6–10 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 300 mg every 12 hr.
PO (Adults and Children ≥1 yr and 0–5 kg): Initial dose: 1/4–1/6 of the maintenance dose in divided doses; ↑ dose in 10% increments to the maintenance dose with ≥2 wk between dose adjustments for those 1–5 yr; ↑ dose gradually over 4–6 wk to maintenance dose for those ≥6 yr. Maintenance dose: 200 mg every 12 hr.

US Brand Names ⬆ ⬇

Action ⬆ ⬇

Prevents the accumulation of intracellular cystine by favoring conversion to cysteine and cysteine compounds that are able to leave the intracellular space.

Therapeutic effects:

Prevention of damage to organs and tissues (especially kidneys) in patients with nephropathic cystinosis.

Classifications ⬆ ⬇

Therapeutic Classification: cystine depleting agent

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed after oral administration.

Distribution: Distributes into the intracellular compartment.

Metabolism/Excretion: Unknown.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(effect on leukocyte cystine levels)

ROUTE	ONSET	PEAK	DURATION
PO	rapid	1.4 hr‡	5–6 hr

‡Blood levels.

Patient/Family Teaching ⬆ ⬇

Instruct patient or parents to take cysteamine exactly as directed. If a dose is missed, take as soon as possible unless within 2 hrs of next dose (Cystagon) or <4 hrs before next dose (Procysbi). Do not double doses.
Instruct patient to remain well-hydrated (2–3 L/day).
May cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Advise patient to notify health care professional immediately if signs and symptoms of benign intracranial hypertension (headache, tinnitus, dizziness, nausea, double vision, blurry vision, loss of vision, eye pain), drowsiness, fever, increased thirst, nausea or vomiting, rash, sore throat, trembling, or seizures occur.
Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications and avoid alcohol during therapy.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected, and to avoid breastfeeding during therapy.
Emphasize the importance of routine lab tests to monitor progress and side effects.

section name header

Indications ⬇

Contraind./Precautions ⬆ ⬇

Adv. Reactions/Side Effects ⬆ ⬇