Scopolamine

From DrugPedia: A Wikipedia for Drug discovery

Current revision

Scopolamine Hydrobromide

( Hyoscine Hydrobromide ) Pronouncation: (skoe-PAHL-uh-meen HIGH-droe-BRO-mide)

Class: Belladonna alkaloid, Cycloplegic mydriatic, Anticholinergic

Trade Names:

Isopto Hyoscine

- Ophthalmic solution 0.25%

Trade Names:

Scopace'

- Tablets, soluble 0.4 mg

Trade Names:

Transderm-Scōp

- Transdermal system 1.5 mg

Transderm-V (Canada)

[edit] Pharmacology

Competitively inhibits action of acetylcholine at muscarinic receptors. Principal effects are on iris and ciliary body (pupil dilations and blurred vision), secretory glands (dry mouth), drowsiness, euphoria, fatigue, decreased nausea, and vomiting.

[edit] Pharmacokinetics

Absorption

Scopolamine is well absorbed percutaneously. T max is reached within 24 h; C max is 87 pg/mL (free scopolamine) and 354ߙpg/mL (total scopolamine).

Distribution

Scopolamine crosses the placenta and the blood-brain barrier. It may be reversibly bound to plasma proteins.

Metabolism

Scopolamine is extensively metabolized and conjugated with less than 5% of the total dose appearing unchanged in urine.

Elimination

Less than 10% of the total dose is excreted in urine as parent and metabolites over 108 h; t ½ is 9.5 h.

[edit] Indications and Usage

As an anticholinergic CNS depressant, symptomatic treatment of postencephalitic parkinsonism and paralysis agitans, in spastic states and locally as a substitute for atropine in ophthalmology, to inhibit excessive motility and hypertonus of the GI tract in such conditions as irritable colon syndrome, mild dysentery, diverticulitis, pylorospasm, and cardiospasm, and may prevent motion sickness (oral); accomplishment of cycloplegia and mydriasis for diagnostic procedures and for preoperative and postoperative states in treatment of iridocyclitis (ophthalmic use); prevention of nausea and vomiting associated with motion sickness and recovery from anesthesia and surgery (transdermal); antiemetic, preanesthetic sedation, antisecretory action, obstetric amnesia in conjunction with analgesics and to calm delirium (parenteral).

[edit] Contraindications

Hypersensitivity to any product component, angle-closure glaucoma; adhesions between iris and lens; children with previous severe reaction to atropine.

[edit] Dosage and Administration

Oral

Adults

0.4 to 0.8 mg.

Ophthalmic

Adults

1 to 2 gtt of 1% solution into eye 1ߙh prior to refraction, or 1 to 2ߙgtt up to 4 times daily for uveitis.

Transdermal

Adults

One transdermal patch placed behind ear at least 4 h prior to event. Wear only 1 patch at a time. Approximately 1 mg will be delivered for 3 days. To prevent postoperative nausea and vomiting, apply patch in the evening before scheduled surgery. To minimize exposure of the newborn baby to the drug, apply the patch 1 h prior to cesarean section. Only 1 patch should be worn at any time. Do not cut patch.

Parenteral

Adults

IM/IV/Subcutaneous 0.32 to 0.65 mg.

IM/IV/Subcutaneous For obstetric amnesia or preoperative sedation, 0.32 to 0.65 mg. For sedation or tranquilization, 0.6 mg 3 or 4 times daily. As an antiemetic, subcutaneous 0.6 to 1 mg.

Children

IM/IV/Subcutaneous 0.006 mg/kg (max, 0.3 mg). IM/IV/Subcutaneous As an antiemetic, subcutaneous 0.006 mg/kg.

Children 6 mo to 3 yr of age

IM/IV/Subcutaneous 0.1 to 0.15 mg.

Children 3 to 6 yr of age

IM/IV/Subcutaneous 0.2 to 0.3 mg.

[edit] Storage/Stability

Store tablets at controlled room temperature (59° to 86°F). Store patches in foil wrapper at controlled room temperature (68° to 77°F). Store ophthalmic solution at controlled room temperature (less than 86°F). Protect from light. Protect injection solution from light with opaque covering until contents have been used. Store vials at controlled room temperature (59° to 86°F). Protect from light.

[edit] Drug Interactions

Haloperidol

Worsened schizophrenia, decreased haloperidol levels, and tardive dyskinesia may occur.

IV incompatibilities

Solutions are incompatible with alkalies. Other drugs capable of causing CNS effects (eg, alcohol, belladonna alkaloids, muscle relaxants, sedatives, tranquilizers)

Use with caution.

Phenothiazines

Actions of phenothiazines may be decreased.

Laboratory Test Interactions

Scopolamine will interfere with the gastric secretion test.

[edit] Adverse Reactions

Cardiovascular

Increased heart rate.

CNS

Drowsiness; disorientation; dizziness; delirium; restlessness; tremors; locomotor difficulties.

Dermatologic

Contact dermatitis; erythema; flushing.

EENT

Blurred vision; stinging; increased IOP; photophobia; conjunctivitis; local irritation including follicular conjunctivitis, vascular congestion, edema, exudates, and an eczematoid dermatitis (ophthalmic use).

GI

Dry mouth.

Genitourinary

Urinary retention.

Respiratory

Decreased respiratory rate.

[edit] Precautions

Pregnancy

Category C .

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established for transdermal use. Use with caution in children and infants.

Elderly

Use with caution in elderly patients.

Hypersensitivity

Contact dermatitis for transdermal system has been reported. Potentially alarming idiosyncratic reactions may occur with therapeutic doses.

Special Risk Patients

Use with caution in men with prostatic hypertrophy and in patients with tachycardia or other tachyarrhythmias, coronary heart disease, congestive heart disease, pyloric obstruction, urinary bladder neck obstruction, history of seizures or psychosis, impaired liver or kidney function; use with caution when administering an antiemetic or antimuscarinic agent.

Photosensitivity

Dim room lights or provide sunglasses if patient experiences photophobia.

Diabetes

Use with caution in those with diabetes.

Glaucoma

Use with caution in those with open-angle glaucoma.

Thyroid abnormalities

Use with caution in thyroid abnormalities.

Other

Dizziness, nausea, vomiting, headache, and disturbances with equilibrium have been reported upon discontinuation after several days of use.

[edit] Overdosage

Symptoms

Coma, convulsions, delirium, dilated pupils, disorientation, dizziness, dry mouth, hallucinations, hyperpyrexia, hypertension, memory disturbances, nausea, restlessness, somnolence, supraventricular arrhythmias, tachycardia, vomiting.

[edit] Patient Information

• Caution patient not to change the dose or stop taking it unless advised by health care provider. Advise patient to notify health care provider if symptoms do not improve or appear to worsen, or if bothersome side effects occur.

• Instruct patient to stop taking the drug and notify health care provider immediately if any of the following occur: rash, flushing, eye pain, inability to urinate, confusion, disorientation, hallucinations, change in behavior.

• Advise patient to avoid strenuous activity during periods of high temperature or humidity.

• Advise patient to take sips of water, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs.

• Inform patient that medication may cause pupils to dilate, resulting in intolerance to bright lights or sunlight. Advise patient to wear dark glasses to make bright lights or sunlight tolerable.

• Advise patient that drug may cause drowsiness, disorientation, or blurred vision and to use caution while driving or performing other tasks requiring mental alertness and coordination until tolerance is determined.

• Transdermal system

• Advise patient to read the patient information leaflet before using patch the first time and with each refill.

• Caution patient to apply 1 patch at a time.

• Instruct patient not to remove patch from foil wrapper until just prior to application.

• Advise patient that in order to prevent motion sickness, the patch must be applied at least 4 h prior to expected motion.

• Instruct patient to follow application instructions and apply to clean, hairless, dry area behind ear. Caution patient not to touch exposed adhesive area of patch and to wash hands thoroughly before and after application.

• Instruct patient to change patch every 72 h if continuation of therapy is required and to rotate application sites.

• Advise patient to wash hands and old application site thoroughly with soap and water after removing patch.

• Advise patient that if patch becomes dislodged to discard patch and apply a fresh patch to hairless area behind other ear.

• Oral

• Advise patient to take prescribed dose 30 to 60 min before meals but to take with food if stomach upset occurs.

• Advise patient that dose and/or frequency of use may be changed periodically to achieve max benefit.

• Ophthalmic

• Remind patient or caregiver that solution is for use in the eye only.

• Teach patient or caregiver proper technique for instilling ophthalmic solution: wash hands; do not allow tip of dropper bottle to touch eye, eyelid, fingers, or any other surface. Tilt head back, look up; pull lower eyelid down to form pocket; place prescribed number of drops in the pocket; look downward before closing eye; compress lacrimal sac for 2 to 3 min after instillation complete. Caution patient not to rub eye(s).

• Advise patient or caregiver that if more than 1 topical ophthalmic drug is being used, instill eye drops first, wait at least 5 min, and then instill ointment last.

• Caution patient that blurred vision may occur and not to drive or engage in hazardous activities while pupil(s) are dilated.

• Advise patient or caregiver to contact health care provider if eye drops cause intolerable stinging, if eye or eyelid inflammation is noted, or if eye symptoms do not improve or worsen.

• Injection

• Advise patient or caregiver that medication will be prepared and administered by a health care provider in a medical setting.

[edit] See Also

[edit] References