Drug Interaction:
BARBITURATES- INCLUDES-
Amobarbital, Aprobarbital Butabarbital , Mephrobarbital, Methabarbital, Pentobarbital,Phenobarbital, Secobarbital, Refer - Phenobarbitone
Interacting drugs - Summary
Phenobarbitone +
Phenobarbital + Cimetidine
Coadmin led to decreased activity
Phenobarbitone + Pyridoxine
Phenobarbital serum level decreased.
Phenobarbitone + Paroxetine
Phenobarbirtal decreased the AUC and half-life of paroxetin
Phenobarbitone + Lamotrigine
Lamotrigine concentration is decreased
Phenobarbitone + Tacrolimus
Decrease tacrolimus blood levels
Valproic acid + Phenobarbitone
Concurrent use result in increased phenobarbital levels and CNS activity
Indication:
Sedative
BARBITURATES- INCLUDES-
Amobarbital, Aprobarbital Butabarbital , Mephrobarbital, Methabarbital, Pentobarbital,
Phenobarbital, Secobarbital,
Refer - Phenobarbitone
Adverse Reaction:
CNS -
Somnolence 3% agitation, confusion, kyperkinesia, CNS depression, nightmares, nervousness, psychiatric disturbances, hallucination, insomina, anxiety, dizziness, abnormal thinking, headache, fever ( esp with chronic phenobarbital use ( < 1%) verigo, lethargy, residual sedation, drowsiness
Respiratory-
Hhypoventilation, apnea, ( < 1% ) , circulatory collapse, respiratory depression Cardiovascular - bradycardia, hypotension, syncope ( < 1% )
GI-
Nausea, vomiting, constipation, ( < 1% ) liver damage particularly with chronic phenobarbital use ( < 1% )
Hypersensitivity-
Skin rashes, angioedema ( particularly following phenobarbital use ( < 1% ) exfolitative dermatitis, ( eg. Stevens - Johnson syndrome and toxic epidermal necrolysis ) may be caused by phenobarbital and may be fatal ( rare )
Hypersentivity reactions - localised swelling, particularly in the eyelids, cheeks or lips, and erythematous dermatitis. The skin eruptions may be assiciated with fever, delirium, and marked degenerative changes in liver and other parenchymatous organs.
Local - inadvertent intra-arterial injection may produce arterial spasm with the resultant therombosis and gangrene of an extremity.
Reactions range from transient pain to severe tissue necrosis, pain, tenderness and redness
Thrombosis after IV use and pain at IM site have been reported
Hematologic:
Megaloblastic anemia (rarely following chronic phenobarbital use)
Contra-Indications:
Hypertension
.Acute intermittant porphyria,severe renal and hepatic disorders.
Severe mycardial damage
.Concurrant admn of drugs acting on CNS.
Special precautions:
1st trimester of pregancy.
Dependence.Do not drive or operate machinery.
Withdrawl syndrome.
Dosages/ Overdosage Etc:
Indications:
Sedative
Dosage:
Adults - Day time sedation 30 to 120mg 2 to 3 times daily.
Children -
Preoperative sedation - 1 to 3mg/kg
Other Information:
For Availability/supplies
Contact -
1.Indian Drug Manufacturers Association (IDMA)
Phone- 022- 24944624/ 24974308
Fax- 022- 24950723
Email- idma@vsnl.com
Website: www.idma-assn.org
2.Bulk Drug Manufacturers Association (India)(BDMA)
Phone - 040-23703910/ 23706718
Fax- 040-23704804
Email- info@bdmai.org
Website: www.info@bdmai.org
Patient Information:
1. Do not increase the dose of the drug without consulting a physian
. 2. Barbiturates may impair mental or physical abilities required for performance of potentially hazardous tasks(driving,operating machinery).
3.Alcohol should not be consumed while taking barbiturates. Concurrent use of barbiturates with other CNS depressants(eg.alcohol,narcotics,tranquilizers,and antihistamines) may result in additional CNS depressant effects
4. Notify the physician if the following occurs: fever,sore throat, mouth sores,easy bruising or bleeding,tiny broken vessels under the skin.
5. Use as aid to sleep is limited; do not use for more than 2 weeks.
6. Allergy- tell your doctor,if youever had an unusual or allergic reaction to barbiturates or to any substances such as food, presrvatives, or dyes.
7.Pregnancy- barbiturates have been shown to incr the chance of birth defects in humans. However this medicine may be needed in serious diseases or other situations that threaten mothers life. Be sure tat you have discussed this with yourdoctor with the the following informaton-
Taking barbiturate regularly during pregnancy may cause bleeding problems in the new born infants.
Also taking barbiturates regularly during the last 3 mths of pregnancy mav cause the baby to become dependent on the medicine.
8. Breast feeding- barbiturates pass into breast milk and may cause drowsiness, slow heart beat, shortness of breath or troubled breathing in babies of nursing mothers taking this medicine
9. Children- unusual excitement may be more likely to ocur inchildren,who are usually more sensitive than adults to the efects of barbiturates
10. Older adults- confusion, mental depression and unusual excitemet may be morelikely to occur in the elderly who are usualy more sensitive than younger adults to the effects of barbiturates
11.Other medicines- tell your doctor if you are taking any of the following medicines medicines - Adrenocorticosteroids or Anticoagulants or Carbamazepine or Corticotropin ACTH - barbiturates may decrease theeffect of these medicines
Cental nervous system CNS depressants (causing drowsiness )- using these medicines with barbiturates may result in increased CNS depressant effect
12. Other medical problems- tell your doctor if you have any other medical problems especially- Alcohol abuse or history of or drug abuse orependence - dependence of barbiturates may develop Anemia or Asthma , emphysema, or other chroic lung disease
13. Dosing- Follow the doctors instructios
14. Missed dose- if you taking this medicine regularly and you miss a dose, take it as soon as possible. However if it is amost time for the next dose, skip the missed dose and go back to your normal schedule Do no double doses.
15. Storage- Keep te medicines away from children Do not store the capsule or tablets in the barth room or near the sink or in damp places. Dampness and heat will cause the medicine to break down Do not keep outdated or unwanted medicines. Make sure that all discarded medicines are kept out of reach of children.
Pharmacology/ Pharmacokinetics:
Ref- Drugs Facts And comparisons(2010)
Barbiturate Includes-
Amobarbtal, Aprobarbital, Butabarbital,Mephobarbital, Methabarbital,
Phenobarbital, Phenobarbital,Secobarbital
Refer- Phenobarbitone
Pharmacology:
Barbiturates can produce all levels of CNS mood alteration from excitation to mild
sedation,hynosis and coma. In suffciently high therapeutic doses barbiturates induce
anesthesia. Overdose can produce death.
Pharmacokinetics:
Barbiturates are absorbed in varying degrees following oral, rectal or parenteral administration.
The salts are more rapidly absorbed than the acids. The rate of absorption is increased if the sodium salt is ingested as a dilute solution or taken on an empty stomach.
Pharmacokinetics of Sedatives and Hynotic barbiturate
Half-life (h) Oral dosage (range mg) Onset Duration
Range Mean Sedative Hypnotic (min) (h)
Drug
Barbiturate- Long Acting
Mephobarbital
11 to 67 34 32 to 200 - 30 to >60 10 to 16
Phenobarbital
53 to 118 79 30 to 120 100 to 320 do do
Barbiturate - Intermediate acting
Amobarbital
18 to 40 25 - - 45 to 60 6 to 8
Butabarbital
66 to 140 100 45 to 120 50 to 100 do do
Barbiturate - Short acting
Phenobarbital
15 to 50 1 40 to 120 100 10 to 15 3 to 4
Secobarbital
15 to 40 28 - 100 do do
Interaction with Food:
Not available
Pregnancy and lactation:
Pregnancy:
Barbiturates can cause fetal damage when administered to a pregnant woman. If the drug is used during pregnancy or if the patient becomes pregnant while taking the drug,appraise her of the potential hazard to the fetus.
Lactation:
Excercise caution when administering to the nursing mother,since small amounts are excreted in breast milk. Drowsiness in the nursing infant has been reported.