What Factors Affect Fluoxetine Dosages?
Fluoxetine is a widely used selective 5-HT reuptake inhibitor (SSRI) that can selectively inhibit 5-HT transporters and block 5-HT reuptake by presynaptic membranes Prolongs and increases the effects of 5-HT, resulting in antidepressant effects. It has low affinity for adrenergic, histaminergic and cholinergic receptors, and its effect is weak, so it has fewer adverse reactions. It is well absorbed after oral administration, with a bioavailability of 70%, and easily crosses the blood-brain barrier, and a small amount can be secreted into milk. It is metabolized in the liver by CYP2D6 to produce norfluoxetine, which also has antidepressant effects.
Basic Information
- Drug Name
- Fluoxetine
- Foreign name
- Fluoxetine
- Molecular formula
- C17H18F3NO
- Molecular weight
- 309.33
- inventor
- David Wong
Fluoxetine indications
- Applicable to depression and the accompanying anxiety, especially suitable for elderly depression.
- Used for the treatment of obsessive-compulsive disorder, but the drug dose should be increased accordingly.
- suitable for bulimia nervosa.
- It is used to treat panic states and has certain effects on generalized anxiety disorder.
Clinical application of fluoxetine
- Oral: 20 mg / day. For the treatment of obsessive-compulsive disorder, 20-60 mg / day. For treatment (bulimia nervosa), 60 mg / day. The daily dose of the elderly should generally not exceed 40 mg. The maximum recommended daily dose is 60 mg.
Fluoxetine adverse reactions
- Adverse reactions were mild and well tolerated at high doses. Common adverse reactions include insomnia, nausea, irritability, headache, exercise anxiety, mental stress, tremor, etc., which mostly occur in the early stage of medication. Sometimes a rash (3%). When large doses (40 to 80 mg per day) are used, psychiatric symptoms can occur, and about 1% of patients develop mania or hypomania. Long-term medication often results in decreased appetite or decreased sexual function.
Fluoxetine precautions
- Antidepressant effects generally do not show up until 4 weeks. Fluoxetine can be administered in single or divided doses. It can be taken with food or between meals. Attention should be paid to closely observe the abnormal behavior and mental and emotional abnormalities of patients during the application of the drug, especially in the initial period and the period of dose change, to detect and stop the occurrence of malignant events in time. Patients with a history of epilepsy, a history of bidirectional affective disorder, acute heart disease, suicidal tendency, and bleeding tendency should be used with caution. Use with caution in children, pregnant women and lactating women. It is not advisable to drive a vehicle or operate a machine while taking medication.
Contraindication to fluoxetine
- Those who are allergic to this product are prohibited.
Fluoxetine Drug Interactions
- 1. SSRIs are prohibited from being used in combination with MAOIs. Prohibit the use of another drug within 14 days of stopping SSRIs or MAOIs, otherwise 5-HT syndrome may be caused.
- 2. Combination with other 5-HT active drugs may increase and lead to hyperactivity of 5-HT energy nerve, and 5-HT syndrome appears.
- 3. Combined with cisapride, thioridazine, pimozide, and terfenadine, it will cause cardiac toxicity, lead to prolonged QT interval, and cardiac arrest. Should not be combined.
- 4. Inhibitors or substrates with CYP2D6 or other CYP isoenzymes (such as cimetidine, amitriptyline, clozazone, perphenazine, maprotiline, imipramine, ritonavir , Buspirone, alprazolam, etc.) can increase the blood concentration of this product.
- 5. Combined with CYP inducers (such as carbamazepine, phenobarbital, phenytoin, etc.), it will reduce the blood concentration and efficacy of this product.
- 6. Combined with hypoglycemic drugs, can lower blood sugar and even cause hypoglycemia. Glucose rises when this product is stopped. Therefore, after using this product and stopping the drug for a period of time, blood glucose levels should be monitored and intervention measures taken in a timely manner.
- 7. SSRIs, 5-HT, and NA dual reuptake inhibitors (SNRIs) all increase the risk of bleeding, especially when combined with aspirin, warfarin, and other anticoagulants.
- 8. Combination with digoxin may increase its blood concentration and increase the risk of digitalis poisoning.
- Note: The above content is only for introduction, the drug use must be carried out by a regular hospital under the guidance of a doctor.