Drugs List

Therapeutic Indications

Uses

To dissolve corneal cystine crystals

Contraindications

Children under 2 years

Precautions and Warnings

Soft contact lenses
Breastfeeding
Pregnancy

Advise patient blurred vision may affect ability to drive/operate machinery
Contains benzalkonium chloride - may cause keratopathy
Administer other ophthalmic products at least 10 minutes apart
To reduce systemic absorption compress lacrimal sac during administration
Monitor leucocyte cystine levels regularly
Advise patient to avoid touching the eye/other surfaces with container tip
If soft contact lenses worn,insert them 15 minutes after using eye drops

Pregnancy and Lactation

Pregnancy

Use mercaptamine eye drops with caution in pregnancy.

Animal studies have shown reproductive toxicity, including teratogenesis. The risk for humans is unknown. The effect of untreated cystinosis in human pregnancy is also unknown.

The manufacturer notes oral mercaptamine is not recommended in pregnancy, however systemic exposure following ocular administration is lower than oral administration.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Use mercaptamine eye drops with caution in breastfeeding.

It is not known whether mercaptamine is excreted in human breast milk.

The manufacturer notes that oral mercaptamine is not recommended in breastfeeding, however systemic exposure following ocular administration is lower than oral administration.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abnormal sensation in eye
Blurred vision (transient)
Corneal deposits
Dry eyes
Eyelid oedema
Eyelid reaction
Hordeolum
Increased lacrimation
Ocular discomfort
Ocular hyperaemia
Ocular irritation
Ocular pain
Ocular pruritus
Sensation of foreign body in eye
Sticky eyelid
Sticky sensation of the eye
Visual impairment (irreversible)

Presentation

Eye drops containing mercaptamine.

Drugs List

Therapeutic Indications

Uses

To dissolve corneal cystine crystals

Dosage

Adults

Children

Contraindications

Children under 2 years

Precautions and Warnings

Soft contact lenses
Breastfeeding
Pregnancy

Advise patient blurred vision may affect ability to drive/operate machinery
Contains benzalkonium chloride - may cause keratopathy
Administer other ophthalmic products at least 10 minutes apart
To reduce systemic absorption compress lacrimal sac during administration
Monitor leucocyte cystine levels regularly
Advise patient to avoid touching the eye/other surfaces with container tip
If soft contact lenses worn,insert them 15 minutes after using eye drops

Pregnancy and Lactation

Pregnancy

Use mercaptamine eye drops with caution in pregnancy.

Animal studies have shown reproductive toxicity, including teratogenesis. The risk for humans is unknown. The effect of untreated cystinosis in human pregnancy is also unknown.

The manufacturer notes oral mercaptamine is not recommended in pregnancy, however systemic exposure following ocular administration is lower than oral administration.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Use mercaptamine eye drops with caution in breastfeeding.

It is not known whether mercaptamine is excreted in human breast milk.

The manufacturer notes that oral mercaptamine is not recommended in breastfeeding, however systemic exposure following ocular administration is lower than oral administration.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abnormal sensation in eye
Blurred vision (transient)
Corneal deposits
Dry eyes
Eyelid oedema
Eyelid reaction
Hordeolum
Increased lacrimation
Ocular discomfort
Ocular hyperaemia
Ocular irritation
Ocular pain
Ocular pruritus
Sensation of foreign body in eye
Sticky eyelid
Sticky sensation of the eye
Visual impairment (irreversible)

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: November 2017

Reference Sources

Summary of Product Characteristics: Cystadrops 3.8mg/ml eye drops. Orphan Europe (UK) Limited. Revised February 2017.