Brand names Catapres, Catapres Periongets, Dixarit
Used in the following combined preparations None
GENERAL INFORMATION
Clonidine has central and peripheral actions in the body. The drug decreases impulses from the brain that keep blood pressure up, and increases activity in nerve pathways that help lower blood pressure. Clonidine has also been given for other conditions such as migraine, menopausal hot flushes, and withdrawal symptoms during drug detoxification.
Its main drawback is that, when used in the doses required to control blood pressure, there may be a severe rise in blood pressure if doses are missed or if the drug is stopped suddenly. Its use to treat hypertension has largely been
superseded by other drugs.
INFORMATION FOR USERS
Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.
How taken
Tablets, SR-capsules, injection. Frequency and timing of doses
1-3 x daily.
Adult dosage range
High blood pressure 0.15mg -1,2mg daily. Doses of up to 2.4mg daily have been used in some resistant cases. Migraine 100-150mcg daily.
Onset of effect
2-5 hours (by mouth); 10 minutes (injection).
Duration of action
6-20 hours.
Diet advice
None.
Storage
Keep in a closed container in a cool, dry place away from the reach of children.
Missed dose
Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.
Stopping the drug
Do not stop taking the drug without consulting your doctor, who will supervise a gradual reduction in dosage. Abrupt withdrawal may cause a dangerous rise in blood pressure.
Exceeding the dose
An occasional unintentional extra dose is unlikely to cause problems. You may experience vomiting or drowsiness. Notify your doctor.
POSSIBLE ADVERSE EFFECTS
Clonidine may cause drowsiness, dry mouth, and constipation. These effects usually decrease after long-term therapy. An adjustment in dosage may help.
QUICK REFERENCE
Drug group Antihypertensive drug and drug for migraine
Overdose danger rating Medium
Dependence rating Low
Prescription needed Yes
Available as generic No
SPECIAL PRECAUTIONS
Be sure to tell your doctor if:
You have had depression.
You have poor circulation. You have heart problems.
You are taking other medications.
Pregnancy
No evidence of risk, but other drugs might be more suitable. Discuss with your doctor.
Breast-feeding
The drug passes into the breast milk and may affect the baby. Discuss with your doctor.
Infants and children
Not recommended.
Over 60
No special problems.
Driving and hazardous work
Avoid such activities until you have learned how clonidine affects you because the drug can cause drowsiness.
Alcohol
Avoid. Alcohol may increase the sedative effects of this drug.
INTERACTIONS
Tricyclic antidepressant drugs may reduce the effect of clonidine.
Sedatives
The sedating effects of clonidine are likely to be enhanced if other drugs with a sedative effect are taken.
Beta blockers
There is an increased risk of a serious rise in blood pressure if clonidine is stopped.
PROLONGED USE
The more common adverse effects, such as drowsiness, constipation, and dry mouth, may decrease with long- term use.
