Name of the Miscellaneous Anti-diuretics Drugs
- Carbamazepine
- Indomethacin
1.Carbamazepine
| Carbamazepine |
| Availability Capsules (extended-release): 100 mg, 200 mg, 300 mg Oral suspension: 100 mg/5 ml Tablets: 200 mg Tablets (chewable): 100 mg Tablets (extended-release): 100 mg, 200 mg, 400 mg |
| Indications and dosages ➣ Prophylaxis of generalized tonicclonic, mixed, and complex-partial seizures Adults and children ages 12 and older: Initially, 200 mg P.O. b.i.d. (tablets) or 100 mg q.i.d. (oral suspension). Increase by up to 200 mg/day q 7 days until therapeutic blood levels are reached. Usual maintenance dosage is 600 to 1,200 mg/day in divided doses q 6 to 8 hours. In children ages 12 to 15, don’t exceed 1 g/day. Give extendedrelease forms b.i.d. Children ages 6 to 12: Initially, 100 mg P.O. b.i.d. (tablets) or 50 mg q.i.d. (oral suspension). Increase by up to 100 mg weekly until therapeutic levels are reached. Usual maintenance dosage is 400 to 800 mg/day. Don’t exceed 1 g/ day. Give extended-release forms b.i.d. Children younger than age 6: Initially, 10 to 20 mg/kg/day P.O. in two or three divided doses. May increase by up to 100 mg/day at weekly intervals. Usual maintenance dosage is 250 to 350 mg/ day. Don’t exceed 400 mg/day ➣ Trigeminal neuralgia Adults: Initially, 100 mg b.i.d. (tablets) or 50 mg q.i.d. (oral suspension). Increase by up to 200 mg/day until pain relief occurs; then give maintenance dosage of 200 to 1,200 mg/day in divided doses. Usual maintenance range is 400 to 800 mg/day. |
Mechanism of Action
Normally, sodium moves into a neuronal cell by passing through a gated sodium channel in the cell membrane. Carbamazepine may prevent or halt seizures by closing or blocking sodium channels, as shown below, thus preventing sodium from entering the cell. Keeping sodium out of the cell may slow nerve impulse transmission, thus slowing the rate at which neurons fire.
Pharmacokinetics
- Bioavailability: 85% (oral suspension)
- Peak serum time: 4.5 hr (immediate-release tablets); 3-12 hr (extended-release tablets); 1.5 hr (oral suspension)
- Protein bound: 75-90%
- Metabolism: Via hepatic CYP3A4
- Half-life: 25-65 hr (initial dosing); decreases to 10-20 hr after autoinduction; 35-40 hr (extended release)
- Excretion: Urine (72%); feces (28%)
Administration
- Don’t give within 14 days of MAO inhibitor.
- Give tablets with meals; may give extended-release capsules without regard to meals.
- Don’t give with grapefruit juice.
- If desired, contents of extendedrelease capsules may be sprinkled over food; however, capsule and contents shouldn’t be crushed or chewed
Contraindications
- Hypersensitivity to drug or TCAs
- MAO inhibitor use within past 14 days
- Bone marrow depression
- Pregnancy or breastfeeding
Precautions:
- Cardiac disease, hepatic disease, increased intraocular pressure, mixed seizure disorders, glaucoma
- Elderly males with prostatic hypertrophy
- Psychiatric patients.
Adverse reactions
- CNS: ataxia, drowsiness, fatigue, psychosis, syncope, vertigo, headache, worsening of seizures
- CV: hypertension, hypotension, arrhythmias, atrioventricular block, aggravation of coronary artery disease, heart failure
- EENT: blurred vision, diplopia, nystagmus, corneal opacities, conjunctivitis, pharyngeal dryness
- GI: nausea, vomiting, diarrhea, abdominal pain, stomatitis, glossitis, dry mouth, anorexia
- GU: urinary hesitancy, retention, or frequency; albuminuria; glycosuria; erectile dysfunction
- Hematologic: eosinophilia, lymphadenopathy, agranulocytosis, aplastic anemia, thrombocytopenia, leukopenia
- Hepatic: hepatitis Metabolic: syndrome of inappropriate antidiuretic hormone secretion
- Respiratory: pneumonitis
- Skin: photosensitivity, rash, urticaria, diaphoresis, erythema multiforme, Stevens-Johnson syndrome
- Other: weight gain, chills, fever
Patient monitoring
- Monitor patient closely. Institute seizure precautions if drug must be withdrawn suddenly.
- Assess for history of psychosis; drug may activate symptoms.
- Monitor baseline hematologic, kidney, and liver function test results.
- During dosage adjustments, monitor vital signs and fluid intake and output. Stay alert for fluid retention, renal failure, and cardiovascular complications.
- With high doses, monitor CBC weekly for first 3 months and then monthly to detect bone marrow depression.
Patient teaching
- Tell patient that he may sprinkle contents of extended-release capsules over food, but that he shouldn’t crush or chew capsule or contents.
- Advise patient that coating on extended-release capsules may be visible in stools because it isn’t absorbed.
- Tell patient to take drug with meals to minimize GI upset.
- Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.
- Advise patient to avoid excessive sun exposure and to wear protective clothing and sunscreen.
- Inform female patient that drug may interfere with hormonal contraception. Advise her to use alternative birth-control method.
- As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and herbs mentioned above.
Nursing Considerations
- Avoid using carbamazepine in patients with a history of hepatic porphyria because it may prompt an acute attack.
- Use carbamazepine cautiously in patients with impaired hepatic function because it’s mainly metabolized in the liver. Monitor liver function tests, as directed.
- Monitor patient closely for adverse reactions because many are serious.
- Periodically monitor blood carbamazepine level to assess for therapeutic and toxic levels; a blood level of 6 to 12 mcg/ml is optimal for anticonvulsant effects.
- Monitor patient closely for evidence of suicidal thinking or behavior, especially when therapy starts or dosage changes.
- Withdraw carbamazepine gradually to minimize risk of seizures.
2.Indomethacin
| Indomethacin |
| Availability Capsules: 25 mg, 50 mg Capsules (sustained release): 75 mg Oral suspension: 25 mg/5 ml |
| Indications and dosages ➣ Rheumatoid arthritis; osteoarthritis; ankylosing spondylitis Adults: 25 to 50 mg P.O. two or three times daily, not to exceed 200 mg daily; or one 75-mg sustained-release capsule P.O. once or twice daily ➣ Acute gouty arthritis Adults: 50 mg P.O. t.i.d. until pain is tolerable; then reduce dosage rapidly and, finally, discontinue drug. Don’t give sustained-release form. ➣ Acute bursitis or tendinitis of shoulder Adults: 75 to 150 mg P.O. daily in three or four divided doses. Discontinue once inflammation is controlled. |
Mechanism of Action
Inhibits synthesis of prostaglandins in body tissues by inhibiting at least 2 cyclo-oxygenase (COX) isoenzymes, COX-1 and COX-2
May inhibit chemotaxis, alter lymphocyte activity, decrease proinflammatory cytokine activity, and inhibit neutrophil aggregation; these effects may contribute to anti-inflammatory activity
Pharmacokinetics
- Bioavailability: ~100%
- Peak plasma time: 0.5-2 hr; 1.67 hr (Tivorbex)
- Protein bound: 99%
- Metabolized in liver
- Half-life: 4.5 hr (prolonged in neonates)
- Excretion: Urine (60%), feces (>33%)
Administration
- Give with food, full glass of water, or antacids to reduce GI upset.
- Don’t open or crush capsules.
- For arthritis, give up to 100 mg of daily dose at bedtime as needed to reduce nighttime pain and morning stiffness.
- Don’t give sustained-release form to patients with gouty arthritis.
Contraindications
- Hypersensitivity to drug, its components, or other NSAIDs
- Active GI bleeding
- Concurrent diflunisal use
Precautions:
- severe cardiovascular, renal, or hepatic disease
- history of ulcer disease
- elderly patients
- pregnant or breastfeeding patients
- children ages 14 and younger (efficacy not established)
Adverse reactions
- CNS: headache, dizziness, drowsiness, fatigue, vertigo, depression, seizures
- EENT: tinnitus
- GI: nausea, vomiting, diarrhea, constipation, abdominal pain or cramps, dyspepsia, ulcers, GI bleeding
- Other: allergic reactions including anaphylaxis
Patient monitoring
- Assess for dizziness, drowsiness, headache, fatigue, and exacerbation of depression, epilepsy, or parkinsonism.
- Monitor for drug efficacy, indicated by improved joint mobility, pain relief, and decreased inflammation.
- Monitor urine output for marked reduction.
- Watch for signs and symptoms of GI bleeding and ulcers.
Patient teaching
- Tell patient to take with food, full glass of water, or antacid to reduce GI upset.
- Advise patient not to open or crush capsules.
- Inform breastfeeding patient that indomethacin enters breast milk and may cause seizures in infant. Advise her to use a different infant feeding method during therapy.
- Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, balance, and alertness.
- As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.
REFERENCES
- Robert Kizior, Keith Hodgson, Saunders Nursing Drug handbook,1st edition 2024, Elsevier Publications. ISBN-9780443116070
- McGraw Hill- Drug Handbook, Seventh Edition, 2013, McGraw Hill Education Publications,9780071799430.
- April Hazard, Cynthia Sanoski, Davi’s Drug Guide for Nurses -Sixteenth Edition 2019, FA Davis Company Publications,9780803669451.
- Jones and Bartlet, Pharmacology for Nurses, Second Edition, 2020, Jones and Bartlet Learning Publications, ISBN 9781284141986.
- Nursebro.com, Search – Nursebro
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