B pharmacy 4 th sem

1. CARBAMAZEPINE: Medication
Presentation

2. CARBAMAZEPINE: Other names for the
medication and med facts
• Pronounced: kar-ba-MAZ-e-peen
• Other names: Carbatrol, Epitol, Equetro,
Novo-Carbamaz, Tegretol, Tegretol CR,
Tegretol-XR, Teril
• Pharmacologic class: iminostilbene derivative
• Pregnancy risk category: D

3. CARBAMAZEPINE : Chemical structure
• Carbamazepine is an iminostilbene derivative that
is
related chemically to the tricyclic antidepressants
and is structurally similar to phenytoin.
• Chemical name: 5H-Dibenz[b,f]azepine-5-
carboxamide; 5-carbamoyl-5H-dibenz[b,f]azepine
• Molecular formula of carbamazepine: C15H12N2O.
• Molecular weight: 236.26.

4. CARBAMAZEPINE: Available forms
• Capsules (extended-release): 100mg, 200mg,
300mg
• Oral suspension: 100mg/5ml
• Tablets: 200mg
• Tablets (chewable): 100mg, 200mg
• Tablets (extended-release): 100mg, 200mg,
300mg

5. CARBAMAZEPINE: Indications and
Dosages
• Indicated in the treatment of Generalized tonic-
clonic and complex partial seizures, mixed
seizure patterns (except Carbatrol)
• Adults and children older than age 12: Initially,
200mg po BID (conventional or extended-release
tablets), or 100mg po QID of suspension with
meals
• May be increased weekly by 200mg po daily in
divided doses and 12 hr. intervals for extended
release, 6 to 8 hr. doses for conventional tablets
or suspension.

6. CARBAMAZEPINE: Dosage guidelines
recommended for ages 12 to 15 years
and older
• Maximum dosage is 1000 mg daily in children
ages 12 – 15 years of age
• Ages 15 years and older, maximum dosage is
1200 mg
• Usual maintenance dose is 800 to 1200 mg
daily

7. • Children ages 6 to 12: Initially 100 mg po BID
(conventional or extended release) or 50mg
suspension po QID with meals
• Increased at weekly intervals up to 100mg po
TID or QID in divided dosages (BID for
extended release) Maximum is 1000mg daily
• Usual maintenance dose is 400-800 mg daily
or 20/30mg/kg in divided doses TID or QID
CARBAMAZEPINE: Dosage
guidelines recommended 6 to 12
years of age

8. CARBAMAZEPINE: Dosage guidelines
recommended for ages 6 and younger
• Recommended dosages are 10 to 20 mg/kg
BID or TID in divided doses (conventional
tablets) or QID (suspension).
• Maximum dosage is 35 mg/kg in 24 hours

9. CARBAMAZEPINE: Secondary usages
• Acute manic and mixed episodes associated
with bipolar I disorder
• Trigeminal Neuralgia
• Restless Leg Syndrome
• Alcohol Withdrawal

10. CARBAMAZEPINE: Bipolar Disorder
• Given for manic episodes
• Usual dosage is 200mg po BID initially, then
increase by 200mg daily until therapeutic
response is achieved
• Maximum dosage is 1600 mg daily

11. CARBAMAZEPINE: Trigeminal
Neuralgia (except Carbatrol)
• Initially 100 mg po BID tablets (conventional
or extended release) or 50mg suspension QID
with meals
• Increased by 100mg q 12 hrs. for all tablets or
50mg for suspension until pain is relieved
• Maximum dose is 1200 mg daily
• Maintenance dose is usually 200mg – 400mg
po BID
• Carbatrol follows different guidelines

12. CARBAMAZEPINE: Restless Leg
Syndrome and Alcohol Withdrawal
• RLS: Adults 100 to 600mg po daily for up to
six weeks
• Alcohol Withdrawal: Adults 600 to 1200 mg
on day 1 with a taper to “0” over 5 to 10 days.

13. CARBAMAZEPINE: Administration
• Shake suspension well before administering
• Contents of extended release may be
sprinkled over applesauce if difficulty
swallowing
• Only tablets labeled “chewable” should be
crushed or chewed
• Never crush or split tablets/capsules or given
broken or chipped tablets

14. CARBAMAZEPINE: Mechanism of
Action
• Thought to stabilize neuronal membranes and
limit seizure activity by either increasing
efflux or decreasing influx of sodium ions
across cell membranes in the motor cortex
during generation of nerve impulses

15. PHARMACOKINETICS
Absorption by route of exposure
Absorption of carbamazepine from the
gastrointestinal tract is slow and erratic but
almost complete. Oral absorption is more rapid
on a full stomach and slower from tablets than
from solution.

16. CARBAMAZEPINE:
Pharmacodyamics/Pharmacotherapeutics
• Pharmacodyamics: Very similar to Phenytoin
in the fact that the anticonvulsant action of
the drug can occur because of its ability to
inhibit the spread of seizure activity or
neuromuscular transmission in general
• Pharmacotherapeutics: Drug of choice in
adults as well as children for the treatment f
generalized tonic-clonic seizures as well as
simple and complex partial seizures

17. CARBAMAZEPINE: Peak and Half-life
time
• Onset time for all routes is unknown
• Peak time for PO, conventional tablets is 1.5 –
12 hrs. with duration unknown
• Peak time for PO, extended release is 4 – 8
hrs.
• Half-life is 25 to 65 hours with a single dose, 8
to 29 hours with long-term use

18. CARBAMAZEPINE: Adverse Reactions
• CNS: ataxia, dizziness, drowsiness, vertigo, worsening of seizures, confusion,
fatigue, fever, headache, syncope
• CV: arrhythmias, AV Block, heart failure, aggravation of coronary artery
disease, hypertension, hypotension
• EENT: blurred vision, conjunctivitis, diplopia, dry pharynx, nystagmus
• GI: nausea, vomiting, abdominal pain, anorexia, diarrhea, dry mouth, glossitis,
stomatitis
• GU: albuminuria, glycosaria, impotence, urinary frequency, urine retention
• Hematologic: agranulocytosis, aplastic anemia, thrombocytopenia,
eosinphils, leukocytosis
• Hepatic: Hepatitis
• Metabolic: hyponatremia, SIADH
• Respiratory: pulmonary hypersensitivity
• Skin: erythema multiforme, Stevens-Johnson Syndrome, excessive
diaphoresis, rash, urticaria,
• Other: chills

19. CARBAMAZEPINE: Drug to Drug
Interactions
• Atracurium, Cisatracturium, Pancuronium,
Rocuronium, Vecuronium: May decrease the effects
of nondepolarizating muscle relaxant, causing it to be
less-effective
• Cimetidine, Danazol, Diltiazem, Fluoxetine,
Fluvoxamine, Isoniazid, Macrolides, Propoxyphene,
Valproic Acid, Verapamil: May increase
Carbamazepine levels, use together cautiously
• Doxycycline, felbate, Haloperidol, Hormonal
contraceptives, Phenytoin, Theophylline, Tiagabine,
Topiramate, Valproate, Warfarin: May decrease levels
of these drugs, watch for decreased effect closely

20. CARBAMAZEPINE: Specific Drug to
Drug interactions
• Lamotrigine: May decrease level and increase
Carbamazepine level. Monitor closely for clinical
effects and toxicity.
• Lithium: May increase CNS toxicity of Lithium.
Avoid using together
• MAO Inhibitors: May increase depressant and
anti-cholinergic effects. Avoid using together.
• Nefazodone: May increase Carbamazepine levels
and toxicity while reducing Nefazodone levels
and therapeutic benefit. Use together is
contraindicated

21. CARBAMAZEPINE: Effects on Lab
Testing
PATIENTS MUST HAVE TESTING DONE ROUTINELY
TO MONITOR THE FOLLOWING:
• May increase BUN level
• May decrease hemoglobin and hematocrit
• May increase Liver function tests
• Increase eosinophil and white blood cell count
• Decrease thyroid function test
• Decrease granulocyte and platelet counts
• May cause false pregnancy test results

22. CARBAMAZEPINE: Research
In cats, carbamazepine depresses thalamic
potential and bulbar and polysynaptic
reflexes. Its capacity to increase discharges of
noradrenergic neurones may contribute to its
anti-epileptic actions (Rall & Schleifer, 1985).

23. CARBAMAZEPINE: Contraindications
and general cautions
Contraindicated
• Hypersensitivity to this drug or tricyclic
antidepressants
• History of bone marrow suppression
• MAO inhibitor use within 14 days
Use with caution
• Mixed seizure disorder diagnosis (may experience
increase in seizures)
• Hepatic dysfunction

24. CARBAMAZEPINE: Considerations
• Asian patients at greater risk for serious skin
reactions. Screen for HLA-B*1502 allele
before beginning treatment
• Watch for worsening of seizures, especially in
patients with mixed seizure disorders,
including atypical absence seizures
• Watch for worsening of depression, anxiety,
suicidal thoughts or behavior.

25. CARBAMAZEPINE: Black box warning
Aplastic anemia and Agranulocytosis
have
been reported in association with
Carbamazepine therapy. Must obtain
complete pretreatment hematologic testing as
a baseline. If during treatment, patient
exhibits low or decreased WBC or
platelet counts, i.e. any evidence of
suppressed bone marrow,
CONSIDER DISCONTINUING THERAPY

26. CARBAMAZEPINE: Patient assessment
• Assess seizure disorder or trigeminal neuralgia prior to
initiation of medication and routinely during course of
treatment
• Obtain baseline urinalysis, blood urea nitrogen level, liver
function, CBC, platelet and reticulocyte counts, iron levels and
reassess routinely.
• Monitor drug level and drug effects closely, therapeutic level
ranges from 4 to 12 mcg/ml. Toxic level is >15 mcg/ml.
• Monitor the patient’s response to the prescribed drug and
serum levels as indicated.
• Monitor the patient for adverse reactions
• Assess the patients compliance with therapy at each follow-
up visit

27. CARBAMAZEPINE: Patient
teaching
• Take with food to decrease GI distress
• Shake suspension prior to administration
• Never crush or chew extended release form or take broken
or chipped tablets
• Tegretol-XR may appear in stool since it is not absorbed
• Keep medication in original container, tightly sealed, away
from moisture to ensure full effectiveness
• Notify MD immediately if fever, sore throat, mouth ulcers,
excess bruising or bleeding occurs.
• Avoid taking while completing activities that require
alertness (drowsiness is side effect)
• Regular eye exams are recommended to ensure eye health

28. CARBAMAZEPINE: Pharmacy Handout
Per “Medicine Shoppe”, Crossville, TN
• Medication name
• Instruction on how to use handout
• Common brand names
• Warning: May cause fatal skin reaction in
certain ethic groups. Testing for HLA-B 1502
indicated for Asian descent.
• No research listed

29. MY PRESCRIPTION
County Clinic
Name: S. SOSICK Date: August 3,
ind: Partial Complex Seizures
Rx Carbamazepine tablets
Sig 200mg. po BID X 30 days
# 60 (sixty)
Refills 0 1 2 3 4 5 (indicating zero refills)

30. REFERENCES
• International Program on Chemical Safety, Chemical Safety
Information from Intergovernmental Organizations,
“CARBAMAZEPINE” August 3, 2012 retrieved from
http://www.inchem.org/documents/pims/pharm/pim100.ht
m#PartTitle:1.%20%20NAME
• Medicine Shoppe, (2012, July) “Carbamazepine, Patient
Information”
• Nursing 2010 Drug Handbook (2010) Wolters Kluwer,
Lippincott Williams & Wilkins
• Nursing Pharmacology Made Incredibly Easy, 2nd
Ed. (2009) )
Wolters Kluwer, Lippincott Williams & Wilkins