Frequent

Adventious movements, such as choreiform or dystonic movements , Anorexia, nausea and vomiting, with or without abdominal pain and distress, Ddry mouth, dysphagia, dysgeusia, sialorrhea, ataxia, Increased hand tremor, headache,dizziness, numbness, Weakness, and faintness, bruxism, confusion, Insomnia, nightmares, hallucinatons, and delusions, Agitation, and anxiety, malaise, fatigue, euphoria.

Less frequent

Cardiac irregularities or palpitations, orthostatic hypotension, Bradykinesia,(on-off phenomenon) Mental changes,including paranoid idaetion, psychotic episodes, Depression with or without siucidal tendencies, and dementia, Urinary retention, muscle twitching and blepharotrismus, Burning sensation of the tongue, Bitter taste, diarrhea, constipation,flatulence, Flushing skin rash, increased sweating, bizzare breathing Patterns, urinary incontinence, Diplopia, blurred vision, dilated pupils, Hot flushes, weught gain,or loss, Dark sweat or urine Rare- GI bleeding, duodenal ulcer, Hypertension, phlebitis, hemolytic anemia, Agranulocytosis, oculogyric crisis, Sense of stimulation, hiccoughs, Edema, loss of hair, hoarseness, priapism, activation of latent Horners syndrome.

Concomittant adminstration of MAOI depressants,pyridoxine, hypotensive agents including resperine and methyldopa, phenothiazines,butyrophenoones,tricyclic antidepressants, pregnant women,narrow angle glaucoma,melanoma. Special precautions: Heart disease,liver disease,dementia or psychosis. Precautions- Wide angle glaucoma- Patients with chronic wide angle glaucoma may be treated cautiosly with levodopa, if the intraocular pressure is well controlled and the patient is carefully monitored for changes in intraocular pressure during thearpy.

On-Off phenomenon-

some patients who initially respond to levodopa therapy may develop the on-off phenomenon a condition where patients sudenly oscillate between improved clinical status and loss of therapeutic effect. This effect may occur within minutes or hours and is associated with long term levodopa treatment. Warnings Concomittant conditions- Administer cautiously to patients with severe cardiovascular or pulmonary disease, bronchial asthma, occulisive cerebrovascular disease.renal hepatic or endocrine disease, affective disorders, major psychoses, and cardiac errhythmias. Periodically evaluate hepatic, hematopoietic , cardiovascular and renal functions during extended therapy in all patients.

Myocardial infarction- Administer cautiously to patients with a history of myocardial infarction who have residual atrial,nodal or ventricular arrhythmias.

Psychiatric patients- Observe all patients for development of depression with suicidal tendencies. Upper GI hemorrhage- may occur in those patients with a history of peptic ulcer.

Pregnancy- Use only when claerly needed wnd when potential benefits outweigh potential hazards.

Lactation- Do not use in nursing mothers.

Children- safety for use in children < 12 years has not been established

Indications:

Parkinsons disease. drug induced extrapyrimidal disorders.

Dosage:

Initial - 0.5 to 1gm daily, divide into 3 or 4 doses.

Give with food. Increase gradually in increments not exceeding 0.75mg/day every 3 to 7 days.

Do not exceed 8g/day.

Ovedosage- Symptoms/Treatment

1. Employ supportive measures along with gastric lavage.

2. Administer IV fluids judiciously and maintain adequate airway.

3. Monitor ECG carefully observe the patient for possible development of arrhyhthmias.

4. If required, give appropiate antiarrhythmias therapy

5. Considr the possiblity of multiple point ingestion. 

Missed dose-

1. If you miss a dose of this medicine, take it as soon as possible.

2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing schedule.

3. Do not double doses.

Dry mouth-

Drugs causing adverse reactions - ( 385 )

1. Anticholinergics

2. Levodopa

3. Tricyclic antodepressants

4. Clonidine

5. Methyldopa 

Schizophrenic-like or Paranoid reactions-

Drugs causing adverse reactions- ( 388 )

1. Amphetamine

2. Lysergic acid

3. Levodopa

4. Tricyclic antidepressants

5. MAOI 6. Bromides

7. Corticosteroids 

Hypomania, Mania or Excited Reactions-

Drugs causing adverse reactions- ( 388 )

1. Levodopa

2. Sympathomimetics

3. Corticosteroids

4. MAOI

5. Tricyclic antidepressants 

Hallucinatory states-

Drugs causing adverse reactions- ( 388 )

1. Amanatadine

2. Narcotics

3. Pentazocine

4. Levodopa

5. Propranolol

6. Tricyclic antidepressants

7. Meperidine

Levodopa

1.May cause GI upset; take with food.

2.Avoid vitamin products containing B-6(pyridoxine hcl).

3.Observe caution while driving or performing tasks requring alertness.

4.If fainting, lightheadedness or dizziness occurs,avoid suddenchanges in posture. Inform your doctor.

5.Medication may cause darkening of urine or sweat. This efect is not harmful.

6.Allergies- tell your doctor if you have ever had any unusual or allergic reaction to levodopa alone or in combination with carbidopa. Also tell your doctor if you are allergic to any other substances, such as foods, presrvatives or dyes.

7. Diet- for patients taking levodopa by itself- Pyridoxime - (Vitamin B6)- has been found to reduce the effects of levodopa when levodopa is taken by itself. If you are taking levodopa by itself, do not take vitamin products containing vitamin B6 during treatment, unless prescribed by your doctor

8.Pregnancy - studies not done in pregnant women. However, studies in rabbits have shown that levodopa alone or in combination with caridopa causes birth defects.

9.Breast feeding- levodopa pass into breast miolk and may cause unwanted side effects in the nursing baby.

10. Children - no specific information comparing use of levodopa in children with use in other age groups

11. Elderly- elderly people are more sensitive the efects of levodopa and increase the chance of side effects.

12. Other medicines - Let your doctor know what other medicines you are taking, so that he can advice you accordingly. Cocaine- cocaine used by individuals taking levodopa alone or in combination with carbidopa may cause irregular heartbeat Ethotoin or Haloperidol or Mephenytoin or Phenothiazines or Phenytoin - taking these medicines together with levodopa may lessen the effect of levodopa MAOI- taking levodopa while you are taking or within 2 weeks of taking MAOI may cause sudden extremely high blood pressure. At least 14 days should be allowed between stopping treatment with one medicine and starting treatment with the other medicine Pyridoxine Vitamin B6- pyridoxine reverses the effect of levodopa Selegiline- dosage of levodopa and levidopa combination may need to decreased

13. Other medical problems - Tell your doctor if you have any other medical problems especially - Diabetes mellitus- the amount of insulin that you need may change Emphysema-, asthma, bronchitis or Glaucoma or Heart or blood vessel disease or Hormone problems or Melanoma - a type of cancer or Mental illness -levodopa may make the conditions worse Kidney diseasse or Liver disease - higher blood levels of levodopa may occur which may increase the chance of side effects Seizure disorders - risk of seizures may be increased Stomach ulcer - ulcer may occur again

14. Missed dose - If you miss a dose of this medicine, take it as soon as possible. however, if it is almost time for the next dose, skip the missed dose. Do not double doses.

15. 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.

16. 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:

The symptoms of Parkinsons disease are related to depletion of striatal dopamine. Dopamine does not cross the blood brain barrier,however levodopa the metabolic precursor of dopamine does cross the blood-brain barrier. It is decarboxylated into dopamine in the basal ganglia and in the periphery.

Pharmcokinetics:

Levodopa is absorbed from the small bowel;peak levels occur in 0.5 to 2 hours and may delayed in the presence of food. Metabolism: The drug is extensively metabolised in the periphery and by the liver. Plasma half-life ranges from 1 to 3 hours. It is primarily excreted in the urine.

Absorption may be delayed by the presence of food.

Pregnancy:

Safety for use of this drug during pregnancy has not been established. Observe caution while taking this drug.

Lactation:

Do not use in nursing mothers.

Children:

Safety for use in children below 12 years not established.