Drug interactions- summary

+ Buspirone

Fluoxetine + Buspirone

 effects of buspirone may be decreased. Pardoxical worsening of OCD has occurred 

MAO inhibitors

Elevation of blood pressure when taken concomittantly with MAO inhibitors.

Digoxin

Elevates blood digoxin levels slightly.

Alcohol

Avoid alcohol.

CNS agents

Caution with other CNS active agents.

Haloperidol

Elevated BP if used with MAOI. Increases serum haloperidol.

Dizziness,nausea,headache,nervousness, light-headedness,

excitment,parasthesias, sleep disturbances,

chest pain,tinnitus,nasal congestion.

Less sedation and lower potential for dependence compared to other anxiolytics.

Hypersens and lactation.

Special precautions:

Preceding co-administration of MAOIs.

Pregnancy,lactation,

Not for children.

Not in decreased hepatic or renal function.

In patients on benzodiapines withdraw the drug gradually over 6 weeks and then start Buspirone.

Date of Approval     1990

Indications:

Short term treatment anxiety disorders.

Dosage:

15mg daily (5mg 3 times a day.) Do not exceed 60mg/day.

EVIDENCE BASED MEDICINE ( MIMS- April 2003)

Generalised Anxiety Disorder (GAD)

Comparative effectiveness of various Interventions

Definition

1. Excessive worry and tension on most days or atleast for six months

2. With increased motor tension - fatiguability, trembling, restlessness, muscle tension

3. With automatic hyperactivity shortness of breath, rapid heart rate, dry mouth, cold hands and dizziness, but not panic attacks

4. With increased vigilance and scanning- feeling keyed up, increased startling, impaired concentration

Beneficial

1. Cognitive therapy

Likely to be beneficial

1. Buspirone

2. Certain antidepressants ( paroxetine, imipramine,trazodone, venlafaxine )

Trade-off between benefits and harms

1. Benzidiapines

Unknown effectiveness

1. Anti-psychotivc drugs

2. Beta-blockers

KEY BLOCKERS

1. A systemic review of randomised clinical trials (RCTs) has found cognitive therapy with behavoiural interventions is more effective than no treatment, anxiety management training alone, or non-directive therapy. No adverse effects were noticed.

2. One systermic review of randomised clinical trials (RCTs) has found that benzodiapines are clinically effective and rapid treatment for generalised anxiety disorder. One RCT found no significant difference in the effects of slow release alprozolam and bromozepam.

3. RCTs have found that buspirone is effective in GAD. Slower onset compared with benzodiapines is counter balanced by few side efects

4. RCTs have found that imipramine, trazodone, venlafaxine and paroxetine are effective treatments for GAD. One trial has found that paraxetine was more effective than benzodiapines. There is a significant risk of side effects with these drugs.

5. It was found that beta-blockers had not been adequately evaluated in GAD.

BUSPIRONE- 

1.Inform physician if any chronic abnormal movements occur.

2 May cause drowsiness and dizziness. Use caution while driving or performing other tasks requiring alertness.

3.Inform physician if you are pregnant, or planning to become pregnant while taking buspirone.

4. Allergies- Tell your doctor if you had any unusual or allergic reactions to buspirone Tell your doctor if you are allergic to any other substances such as foods, or drinks.

5. Pregnancy- Buspirone has not been studied in pregnant women. However, buspirone has not been to shown to cause birth defects or other problems in animal studies

6. Breast feeding- It is not known whether buspirone passes into breatmilk of humans.

7. Children- Studies on this medicine have been done only on adult patients and there is no specific information comparing use of buspirone in children upto 18 years of age in other age groups

8. Elderly- Not been tested and has not shown to cause different side effects or problems in older people than it does in younger adults

9. Other medicines- Tell your doctor if you are taking any 0ther medicines- Monoamine oxidase inhibitors- taking buspirone while you are taking or within 2 weeks of taking MAOI may cause high blood pressure.

10. Other medical problems- Tell your doctor ifyou have any other medical problems- Drug abuse or depedence - there is a possibility that buspirone could become habit forming causing, mental or physical dependence Kidney or Liver disease- effects of buspirone may be increased which may increase chance of side effects.

11. Missed dose- Itf you are taking this medicine regularly and miss a dose take it as soon as possible However, if it is almost timefor the next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

12. Storage - Keep out of reach of children. Store away from heat or direct sunlight. Do not store the capsule in bathroom, near the kitchen sink, or in other damp places.

13. Outdated medicines - Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of reach of children.

Pharmacology:

Buspirone hcl is an azaspirodecanedione agent not chemically or pharmacologically related to benzodiapines. Mechanism of action is not well known.

Pharmcokinetics:

Buspirone is rapidly absorbed and undergoes extensive first-pass metabolism. Following oral administration,plasma concentration of unchanged buspirone are very low and variable. Peak plasma levels of 1 to 6ng/ml have been observed 40 to 60 minutes after single dose of 20mg.

Administration with food may decrease buspirones rate of absorption.
Take consistently either always with or without meals
 

Pregnancy:

Use during pregnancy only if clearly needed.

Lactation:

The extent of excretion in breast milk of buspirone or its metabolites is not known.