Start PROCYSBI immediately after diagnosis of nephropathic cystinosis1
PROCYSBI® (cysteamine bitartrate) delayed-release capsules and delayed-release oral granules should be initiated immediately following diagnosis of nephropathic cystinosis in patients aged ≥1 year.1
Early treatment can delay or limit damage to the patient’s tissues and organs caused by rising cystine levels, but treatment cannot reverse damage that has already occurred.2-4
Determine dose by patient experience with cysteamine bitartrate1
Patients switching from immediate-release (IR) cysteamine bitartrate should start PROCYSBI by taking a total daily dose equal to his or her previous total daily dose.1
For cysteamine-naïve patients, PROCYSBI should be initiated with a dosage equal to one-sixth to one-fourth of the maintenance dose. The maintenance dosage after initial dose escalation is 1.3 g/m2 of body surface area per day divided into 2 doses given every 12 hours.1
Starting and maintenance dosage of PROCYSBI by body weight1,*
|Weight in kg||Starting PROCYSBI Dosage in mg Every 12 Hours, as a Fraction of the Maintenance Dosage||Maintenance PROCYSBI Dosage in mg Every 12 Hours*|
|⅙ of dosage||¼ of dosage|
|51 and greater||175||250||1000|
*Higher dosages may be required to achieve target therapeutic WBC cystine concentration.
Starting low and slowly increasing the dose may reduce the risk of some adverse events1
- Patients aged 1 year to <6 years: Increase the dosage in 10% increments to the maintenance dosage while monitoring white blood cell (WBC) cystine concentrations. Allow a minimum of 2 weeks between dosage adjustments.
- Patients aged ≥6 years: Gradually increase the dosage over 4 to 6 weeks until the maintenance dosage is achieved.
Regular WBC cystine level testing is the only way to know your patient has the correct dose of PROCYSBI and controlled cystine levels.1,3,4
Adjust dosage as needed
If patients experience tolerability issues when starting PROCYSBI, the dose should be temporarily adjusted as follows1:
- Cysteamine-naïve patients: If a patient experiences initial intolerance, temporarily discontinue PROCYSBI, restart at a lower dosage, and gradually increase dosage.
- Patients switching from IR cysteamine: For patients who may experience temporary intolerance upon starting PROCYSBI, decrease the dosage and then gradually increase to the maintenance dosage.
Ongoing management of cystinosis
Continuous cystine control is critical to limiting the progression of cystinosis. Even brief interruptions in cysteamine dosing allow a rapid return to toxic levels of cystine.5
In a study, patients who delayed their dose of cystine-depleting therapy (CDT) by 3 hours (9 hours vs 6 hours) had WBC cystine levels that were 65% higher and in excess of the target level.5
Comparison of WBC cystine content with 9-hour vs 6-hour dosing of IR cysteamine5
Comparison of morning leukocyte content with IR CDT when administered every 6 hours (8 AM, 2 PM, 8 PM, 2 AM) vs 4 times a day with a 9-hour night pause (8 AM, 1 PM, 6 PM, 11 PM) in a cohort of 22 Dutch patients (mean age 14.7 ± 9.7 years) with nephropathic cystinosis.5
WBC cystine levels should be regularly measured to help ensure optimal PROCYSBI dosing1
To reach the correct maintenance dose, WBC cystine levels should be monitored according to the schedules in the table below. Once patients reach their maintenance dose, cystine levels should be measured at least twice a year for both children and adults.1
|Patients switching from IR cysteamine to PROCYSBI:
||Cysteamine-naïve patients aged 1 year to <6 years:
||Cysteamine-naïve patients ≥6 years:
Maintenance doses may require adjustment to achieve the target WBC cystine levels.1
If the WBC cystine concentration is greater than the target level, consider the following before dose adjustment1:
- Adherence to medication and dosing interval
- The timing between the last dose and the blood draw for the laboratory measurement
- The timing of PROCYSBI administration in relation to food or other administration instructions
Regular WBC cystine level testing is an important element in the effective treatment of cystinosis1,4,7
There are 2 WBC cystine level tests available and they are not interchangeable. It’s recommended to use the same test type each time in order to compare results over time. Be sure to recommend that your patients obtain their blood draw just before they take their next dose of PROCYSBI.1,6,7
|Type of Test||Testing Institution||Test-Specific Target Cystine Level6|
|Granulocytes||University of California San Diego||Less than 1.9 nmol ½ cystine/mg protein|
|Mixed leukocytes||Baylor Genetics||Less than 1.0 nmol ½ cystine/mg protein|
|Obtain WBC sample 12 hours after dosing with PROCYSBI. It is important to accurately record the time of the last dose, the actual dose, and the time the blood sample was taken.|
PROCYSBI offers flexibility in administration, with 3 different ways your patients can take it.1
1 - Swallowed whole
PROCYSBI capsules can be swallowed whole with fruit juice (except grapefruit juice) or water. Do not crush or chew the capsules.1
2 - Opened and mixed with select foods or liquids
For patients who cannot tolerate PROCYSBI on an empty stomach or have difficulty swallowing, capsules or packets should be opened and the microbeads mixed with select foods or liquids.1
3 - Through a G-tube
For individuals with a G-tube that is size 14 French or larger, PROCYSBI capsules or packets should be opened and the microbeads mixed with strained applesauce with no chunks.1
Stomach acidity affects PROCYSBI’s release and absorption
To maintain the right stomach acid levels for continuous cystine control, patients should1:
Take PROCYSBI at least 1 hour before or after they take medicines that contain bicarbonate or carbonate
not eat for at least 2 hours before and 30 minutes after taking PROCYSBI.
Take PROCYSBI with no more than ½ cup (4 oz) of food up to 1 hour before or after they take it, if they cannot tolerate PROCYSBI on an empty stomach.
Patients should be directed to take PROCYSBI correctly for best results. They should1:
- Take PROCYSBI the same way each time
- Not eat for at least 2 hours before and at least 30 minutes after taking PROCYSBI
- Take PROCYSBI with no more than ½ cup (4 oz) of food up to 1 hour before or after they take it, if they cannot tolerate PROCYSBI on an empty stomach
- Take PROCYSBI at least 1 hour before or after they take medicines that contain bicarbonate or carbonate
References: 1. PROCYSBI (cysteamine bitartrate) delayed-release capsules and delayed-release oral granules [prescribing information] Horizon. 2. Nesterova G, Gahl WA. Cystinosis: the evolution of a treatable disease. Pediatr Nephrol. 2013;28(1):51-59. 3. Gahl WA, Balog JZ, Kleta R. Nephropathic cystinosis in adults: natural history and effects of oral cysteamine therapy. Ann Intern Med. 2007;147(4):242-250. 4. Elmonem MA, Veys KR, Soliman NA, van Dyck M, van den Heuvel LP, Levtchenko E. Cystinosis: a review. Orphanet J Rare Dis. 2016;11(47):1-17. 5. Levtchenko EN, van Dael CM, de Graaf-Hess AC, et al. Strict cysteamine dose regimen is required to prevent nocturnal cystine accumulation in cystinosis. Pediatr Nephrol. 2006;21(1):110-113. 6. Gertsman I, Johnson WS, Nishikawa C, Gangoiti JA, Holmes B, Barshop BA. Diagnosis and monitoring of cystinosis using immunomagnetically purified granulocytes. Clin Chem. 2016;62(5):766-772. 7. Langman CB, Barshop BA, Deschênes G, et al. Controversies and research agenda in nephropathic cystinosis: conclusions from a “Kidney Disease: Improving Global Outcomes” (KDIGO) Controversies Conference. Kidney Int. 2016;89(6):1192-1203.