Antimania Drugs

MANIC SYMPTOMSMANIC SYMPTOMS

Elevated  or irritable mood
Increased activity or psychomotor agitation
Reduced need for sleep
Inflated self esteem or grandiosity
Increased or pressure of speech
Flight of ideas

These drugs are used to treat manic-depressive illness.

1. Lithium
2. Carbamazepine
3. Valproic acid

Mechanisms of action

1. Lithium works inside the cell to block conversion of inositol phosphate to inositol.
2. Carbamazepine blocks sodium channels 
3. Valproic acid blocks sodium and calcium channels

PHARMACOKINETICS

Absorbed readily and almost completely from the GI tract; peak concentrations in 1-2 hrs

Lithium toxicity

1. Nausea, diarrhea, convulsions, coma, hyperreflexia, cardiac arrhythmias, hypotension.
2. Thyroid enlargement; increases thyroid stimulating hormone (TSH) secretion; may cause hypothyroidism.
3. Polydipsia, polyuria (lithium inhibits the effect of antidiuretic hormone on the kidney).

Clinical applications concerning lithium 

- Patients must be warned against sodium-restricted diets because sodium restriction leads to greater retention of lithium by the kidney.
- Patients must have regular (e.g., monthly) blood checks because the margin of safety is narrow.

Endocrine Effects – Goitre and hypothyroidism commonly

Cardiac Effects:– ECG changes(common) - T-wave flattening/inversion and appearance of U wavesflattening/inversion and appearance of U waves

Li and Pregnancy -1st Trimester:Cardiovascular anomalies of the newborn, especially Ebstein's malformation
- 3rd Trimester: Neonatal goiter, CNS depression, hypotonia ("floppy baby" syndrome)

Drug–drug interactions of lithium
Diuretics and newer nonsteroidal anti-inflammatory drugs (NSAIDs) reduce lithium excretion and may cause lithium toxicity.

Oxyphenbutazone: one of the metabolites of  phenylbutazone. Apazone.  Similar to  phenylbutazone, but less likely to cause  agranulocytosis

Codeine

Codeine is methyl morphine, with a methyl substitution on the phenolic hydroxyl group of morphine. It is more lipophilic than morphine and thus crosses the blood–brain barrier faster.

• classified as a simple, or mild analgesic, codeine is often used in low doses as an oral analgesic has a much better oral/parenteral absorption ratio than morphine.
• Effective for mild to moderate pain.
• Constipation occurs
• Dizziness may occur in ambulatory patients.
• More potent histamine-releasing action than does morphine.
• Should not be administered by IV injection.
• Extremely effective antitussive agent and is used therapeutically for suppressing cough.
• In contrast to morphine, codeine overdose can occasionally lead to the production of seizures.
• Seizures can be treated with barbiturates.
• Respiratory depression can be counteracted with Naloxone.
• orally, 30 mg of codeine is equi-analgesic to 600 mg of aspirin, however, the effects of the two are additive, and occasionally synergistic

Procoagulant Drugs:

Desmospressin Acetate

• Is a synthetic analogue of the pituitary antidiuretic hormone (ADH).

• Stimulates the activity of Coagulation Factor VIII

• Use for treatment of hemophilia A with factor VIII levels less than or equal to 5%, treatment of hemophilia B or in clients who have factor VIII antibodies. Treatment of severe classic von Willebrand's disease (type I) and when an abnormal molecular form of factor VIII antigen is present. Use for type IIB von Willebrand's disease.

Benzylpenicillin (penicillin G)

Benzylpenicillin, commonly known as penicillin G, is the gold standard penicillin. Penicillin G is typically given by a parenteral route of administration because it is unstable to the hydrochloric acid of the stomach.

Indications :

bacterial endocarditis, meningitis, aspiration pneumonia, lung abscess,community-acquired pneumonia, syphilis, septicaemia in children

Class II Beta Blockers 

Block SNS stimulation of beta receptors in the heart and decreasing risks of ventricular fibrillation
– Blockage of SA and ectopic pacemakers: decreases automaticity 
– Blockage of AV increases the refractory period
- Increase AV nodal conduction ´ 
- Increase PR interval
- Reduce adrenergic activity

Treatment: Supraventricular tachycardia (AF, flutter, paroxysmal supraventricular tachycardia 
– Acebutolol 
– Esmolol 
– Propanolol 

Contraindications and Cautions 

• Contraindicated in sinus bradycardia P < 45
• Cardiogenic shock,  asthma or respiratory depression which could be made worse by the blocking of Beta receptors. 
• Use cautiously in patients with diabetes and thyroid dysfunction, which could be altered by the blockade of Beta receptors 
• Renal and hepatic dysfunction could alter the metabolism and excretion of these drugs.