CITALOPRAM

f. MAXIMUM SAFE PEDIATRIC PHENOBARBITAL DOSE: No maximum safe dose has been established. Children in status epilepticus have received doses of 30 to 120 milligrams/kilogram within 24 hours. Vasopressors and mechanical ventilation were needed in some patients receiving these doses.
g. MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation.
h. NEONATAL PHENOBARBITAL LOADING DOSE: 20 to 30 milligrams/kilogram intravenously at a rate of no more than 1 milligram/kilogram per minute in patients with no preexisting phenobarbital serum levels.
i. NEONATAL PHENOBARBITAL MAINTENANCE DOSE: Repeat doses of 2.5 milligrams/kilogram every 12 hours may be given; adjust dosage to maintain serum levels of 20 to 40 micrograms/milliliter.
j. MAXIMUM SAFE NEONATAL PHENOBARBITAL DOSE: Doses of up to 20 milligrams/kilogram/minute up to a total of 30 milligrams/kilogram have been tolerated in neonates.
k. CAUTIONS: Adequacy of ventilation must be continuously monitored in children and adults. Intubation may be necessary with increased doses.
l. SERUM LEVEL MONITORING: Monitor serum levels over next 12 to 24 hours for maintenance of therapeutic levels (20 to 40 micrograms per milliliter).

5. PHENYTOIN/FOSPHENYTOIN

a. Benzodiazepines and/or barbiturates are generally preferred to phenytoin or fosphenytoin in the treatment of drug or withdrawal induced seizures.
b. PHENYTOIN

(1) PHENYTOIN INTRAVENOUS PUSH VERSUS INTRAVENOUS INFUSION: Manufacturer does not recommend intravenous infusions due to lack of solubility and resultant precipitation, however infusions are commonly used.

(a) Administer phenytoin undiluted, by very slow intravenous push or dilute 50 milligrams per milliliter solution in 50 to 100 milliliters of 0.9 percent saline.

(2) PHENYTOIN ADMINISTRATION RATE: Rate of administration by either method should not exceed 0.5 milligram per kilogram per minute or 50 milligrams per minute.
(3) ADULT PHENYTOIN LOADING DOSE: 15 to 18 milligrams per kilogram of phenytoin initially. Rate of administration by very slow intravenous push or diluted to 50 milligrams per milliliter should not exceed 0.5 milligram per kilogram per minute or 50 milligrams per minute.
(4) ADULT PHENYTOIN MAINTENANCE DOSE: Manufacturers recommend a maintenance dose of 100 milligrams orally or intravenously every 6 to 8 hours. The goal is to maintain a serum concentration between 10 to 20 micrograms/milliliter.
(5) PEDIATRIC PHENYTOIN LOADING DOSE: 15 to 20 milligrams per kilogram or 250 milligrams/square meter of phenytoin. Rate of intravenous administration should not exceed 0.5 to 1.5 milligrams per kilogram per minute.
(6) PEDIATRIC PHENYTOIN MAINTENANCE DOSE: Repeat doses of 1.5 milligrams per kilogram may be given every 30 minutes to a maximum daily dose of 20 milligrams per kilogram.
(7) CAUTIONS: Administer phenytoin while monitoring ECG. Stop or slow infusion if arrhythmias or hypotension occur. Be careful not to extravasate. Follow each injection with injection of sterile saline through the same needle.
(8) SERUM LEVEL MONITORING: Monitor serum levels over next 12 to 24 hours for maintenance of therapeutic levels (10 to 20 micrograms per milliliter).

c. FOSPHENYTOIN

(1) ADULT DOSAGE AND ADMINISTRATION: The dose, concentration in dosing solutions, and infusion rate of fosphenytoin are expressed as phenytoin sodium equivalents.
(2) ADULT LOADING DOSE FOSPHENYTOIN: 15 to 20 milligrams/kilogram of phenytoin sodium equivalents at a rate of 100 to 150 milligrams phenytoin equivalent/minute.
(3) Fosphenytoin should not be infused at rates greater than 150 milligrams phenytoin equivalent/minute because of the risk of hypotension.
(4) CAUTIONS: Perform continuous monitoring of respiratory function, cardiac rhythm, and blood pressure throughout infusion and for at least 30 minutes thereafter.
(5) ADULT MAINTENANCE DOSING: 4 to 6 milligrams phenytoin equivalents/kilogram/day. Rate of administration should not exceed 150 milligrams phenytoin equivalent/minute.
(6) SERUM LEVEL MONITORING: Monitor serum phenytoin levels over the next 12 to 24 hours; therapeutic levels 10 to 20 microgram/milliliter. Do not obtain serum phenytoin concentrations until at least 2 hours after infusion is complete to allow for conversion of fosphenytoin to phenytoin.

B. MONITORING PARAMETERS

1. Despite limited overdose data at the time of this review, QT prolongation and sinus tachycardia following citalopram overdose have occurred. Obtain a baseline ECG, continuous cardiac monitoring and serial ECGs as indicated following significant exposure.
2. Monitor serum electrolytes (including potassium and bicarbonate); metabolic acidosis has occurred following significant exposure.
3. ECG abnormalities including QTc prolongation, sinus tachycardia, and inferolateral repolarization abnormalities have occurred following severe citalopram overdoses (400 mg to 5200 mg) (Grundemar et al, 1997).

C. TORSADE DE POINTES

1. SUMMARY

a. Withdraw the causative agent. Hemodynamically unstable patients require electrical cardioversion. Emergent treatment with magnesium, isoproterenol, or atrial overdrive pacing is indicated. Detect and correct underlying electrolyte abnormalities (hypomagnesemia, hypokalemia, hypocalcemia) (Smith & Gallagher, 1980; Keren et al, 1981; AHA, 2000).

2. MAGNESIUM SULFATE

a. ADULT DOSE: No clearly established guidelines exist. Administer 2 grams (16 mEq) mixed in 50 to 100 milliliters D5W intravenously over 5 minutes, followed if needed by a second 2 gram bolus and infusion of 3 to 50 milligrams/minute in patients not responding to the initial bolus or with recurrence of dysrhythmias (AHA, 2000; Perticone et al, 1997).
b. PEDIATRIC DOSE: 25 to 50 milligrams/kilogram diluted to 10 milligrams/milliliter for intravenous infusion over 5 to 15 minutes.
c. PRECAUTIONS: Use with caution in patients with renal insufficiency.
d. MAJOR ADVERSE EFFECTS: High doses may cause respiratory depression, weakness, neuromuscular blockade, and hypotension.
e. MONITORING PARAMETERS: Heart rate and rhythm, blood pressure, respiratory rate, motor strength, deep tendon reflexes, serum magnesium, phosphorus, and calcium.

3. ISOPROTERENOL

a. DOSE: 2 to 10 micrograms/minute (children: 0.1 to 1 microgram/kilogram/minute) by continuous monitored intravenous infusion; titrate to heart rate and rhythm response. A 2-microgram/milliliter solution may be prepared by mixing 1 milligram isoproterenol hydrochloride in 500 milliliters of dextrose 5 percent in water.
b. AVAILABLE FORMS: Isuprel(R) (parenteral solution) 1:100,000; 1:50,000; 1:5000
c. PRECAUTIONS: Correct hypovolemia before using; do not administer simultaneously with epinephrine; contraindicated in patients with acute cardiac ischemia; may precipitate fatal ventricular fibrillation if the rhythm is not torsade de pointes.

(1) Use caution in patients with coronary insufficiency, diabetes, hyperthyroidism, or sensitivity to sympathomimetics; contraindicated in patients with pre-existing dysrhythmias.

d. MAJOR ADVERSE EFFECTS: Cardiac dysrhythmias, dizziness, nervousness, tremor.
e. MONITORING PARAMETERS: Heart rate and rhythm, blood pressure, central venous pressure

4. OVERDRIVE PACING

a. Institute overdrive pacing at a rate of 130 to 150 beats per minute, and decrease as tolerated.

5. PHENYTOIN

a. ADULT DOSE: 15 milligrams/kilogram intravenous infusion at a rate not exceeding 50 milligrams/minute.
b. PEDIATRIC DOSE: 15 to 20 milligrams/kilogram by intravenous infusion at a rate not exceeding 1 to 3 milligrams/kilogram/minute to a maximum of 50 milligrams/minute.
c. PRECAUTIONS: Too rapid infusion may induce hypotension and dysrhythmias. Extravasation may cause significant tissue injury.
d. MAJOR ADVERSE EFFECTS: Hypotension and dysrhythmias may develop with too rapid infusion. Mild central nervous system depression, nystagmus, and ataxia are common.
e. MONITORING PARAMETERS: Heart rate and rhythm, blood pressure

6. AMIODARONE

a. Despite its prolongation of the QT interval, amiodarone has been reported to be effective in both treating acute episodes of torsades de pointes and preventing recurrences (Mattioni et al, 1989; Lazzara, 1989).

7. OTHER DRUGS

a. Lidocaine, mexiletine, verapamil, bretylium, propranolol, and labetalol have also been used to treat torsade de pointes, but results have been inconsistent.

8. AVOID

a. Avoid class Ia antiarrhythmics (quinidine, disopyramide, procainamide, aprindine) and most class III antiarrhythmics (N- acetylprocainamide, sotalol) since they may further prolong the QT interval and have been associated with torsade de pointes.

D. ACIDOSIS

1. Treat acidosis (less than pH 7.1) with IV sodium bicarbonate. Begin with 1 mEq/kg in adults and in children. Repeat doses of no more than one-half the original amount may be given no more often than every 10 minutes if required. Monitor blood gases to adjust dose.

E. HYPOKALEMIA

1. Monitor potassium following significant exposure; replace as indicated.

F. RHABDOMYOLYSIS

1. SUMMARY: Early aggressive fluid replacement is the mainstay of therapy and may help prevent renal insufficiency. Diuretics such as mannitol or furosemide may be needed to maintain urine output. Urinary alkalinization is NOT routinely recommended.
2. Initial treatment should be directed towards controlling acute metabolic disturbances such as hyperkalemia, hyperthermia, and hypovolemia. Control seizures, agitation, and muscle contractions.
3. Vigorous fluid replacement with 0.9% saline is necessary even if there is no evidence of dehydration. Hypovolemia, increased insensible losses, and third spacing of fluid commonly increase fluid requirements. Strive to maintain a urine output of at least 2 to 3 milliliters/kilogram per hour. In severe cases 500 milliliters of fluid per hour may be required for the first several days. Monitor fluid input and urine output, plus insensible losses. Monitor for evidence of fluid overload and compartment syndrome; monitor serum electrolytes, CK, and renal function tests.
4. Alkalinization of the urine is not routinely recommended as it has never been documented to reduce nephrotoxicity and may cause complications such as alkalemia, hypocalcemia, and hypokalemia.

G. SEROTONIN SYNDROME

1. HYPERTHERMIA

a. Control agitation and muscle activity. Undress patient and enhance evaporative heat loss by keeping skin damp and using cooling fans.
b. MUSCLE ACTIVITY - Benzodiazepines may be useful. Diazepam: Adult: 5 to 10 milligrams IV every 5 to 10 minutes as needed, monitor for respiratory depression and need for intubation. Child: 0.25 milligram/kilogram IV every 5 to 10 minutes; monitor for respiratory depression and need for intubation.
c. Non-depolarizing paralytics may be used in severe cases.

2. HYPERTENSION

a. Monitor vital signs regularly. For mild/moderate asymptomatic hypertension, pharmacologic intervention may not be necessary. For hypertensive emergencies (emergent need to lower mean BP 30 percent within 30 minutes and achieve diastolic BP of 100 mmHg or less within one hour), nitroprusside is preferred.
b. NITROPRUSSIDE

(1) NITROPRUSSIDE/INDICATIONS

(a) Nitroprusside is preferred for hypertensive emergencies (emergent need to lower mean BP 30 percent within 30 minutes and achieve a diastolic BP of 100 mmHg or less within one hour).

(2) NITROPRUSSIDE/DOSE

(a) 0.1 to 5 microgram/kilogram/minute intravenous infusion; up to 10 micrograms/kilogram/minute may be required (AHA, 1992).

(3) NITROPRUSSIDE/SOLUTION PREPARATION

(a) Dilute a 50-milligram vial in 500 milliliters of dextrose 5 percent in water (100 micrograms/milliliter). Prepare fresh every 24 hours; wrap in aluminum foil. Discard discolored solution.

(4) NITROPRUSSIDE/MAJOR ADVERSE REACTIONS

(a) Severe hypotension; cyanide toxicity; methemoglobinemia; lactic acidosis; chest pain or arrhthymias (high doses).

(5) NITROPRUSSIDE/MONITORING PARAMETERS

(a) Monitor blood pressure every 30 to 60 seconds at onset of drip; once stabilized, monitor every 30 minutes.

c. NITROGLYCERIN

(1) In theory, nitroglycerin may help alleviate the serotonin syndrome through nitric oxide mediated downregulation of serotonin.
(2) ADULT - Begin continuous infusion at 5 micrograms/minute and titrate to desired effect.
(3) CHILD - Begin infusion at 0.25 to 0.5 micrograms/kilogram/minute and titrate to desired effect.

3. HYPOTENSION

a. Administer 10 to 20 milliliters/kilogram 0.9% saline bolus and place patient in Trendelenburg position. Further fluid therapy should be guided by central venous pressure or right heart catheterization to avoid volume overload.
b. Control hyperthermia.
c. Pressor agents with dopaminergic effects may theoretically worsen serotonin syndrome and should be used with caution.
d. DOPAMINE

(1) PREPARATION: Add 200 or 400 milligrams to 250 milliliters of normal saline or dextrose 5% in water to produce 800 or 1600 micrograms per milliliter or add 400 milligrams to 500 milliliters of normal saline or dextrose 5% in water to produce 800 micrograms per milliliter.
(2) DOSE: Begin at 2 to 5 micrograms per kilogram per minute progressing in 5 to 10 micrograms per kilogram per minute increments as needed.
(3) CAUTION: If VENTRICULAR ARRHYTHMIAS occur, decrease rate of administration.

e. NOREPINEPHRINE

(1) PREPARATION: Add 4 milliliters of 0.1 percent solution to 1000 milliliters of dextrose 5% in water to produce 4 micrograms/milliliter.
(2) INITIAL DOSE

(a) ADULTS: 2 to 3 milliliters (8 to 12 micrograms)/minute
(b) ADULT AND CHILD: 0.1 to 0.2 microgram/kilogram/minute. Titrate to maintain adequate blood pressure.

(3) MAINTENANCE DOSE

(a) 0.5 to 1 milliliter (2 to 4 micrograms)/minute

4. SEIZURES

a. DIAZEPAM

(1) MAXIMUM RATE: Administer diazepam intravenously over 2 to 3 minutes (maximum rate = 5 milligrams/minute).
(2) ADULT DIAZEPAM DOSE: 5 to 10 milligrams initially, repeat every 5 to 10 minutes as needed. Monitor for hypotension, respiratory depression and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after diazepam 30 milligrams.
(3) PEDIATRIC DIAZEPAM DOSE: 0.2 to 0.5 milligram per kilogram, repeat every 5 minutes as needed. Monitor for hypotension, respiratory depression and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after diazepam 10 milligrams in children over 5 years or 5 milligrams in children under 5 years of age.
(4) RECTAL USE: If an intravenous line cannot be established, diazepam may be given per rectum (not FDA approved), or lorazepam may be given intramuscularly.

b. LORAZEPAM

(1) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 milligrams/minute (Prod Info Ativan(R), 1991).
(2) ADULT LORAZEPAM DOSE: 4 to 8 milligrams intravenously. Initial doses may be repeated in 10 to 15 minutes if seizures persist (AMA, 1991).
(3) PEDIATRIC LORAZEPAM DOSE: 0.05 to 0.1 milligram/kilogram intravenously, repeated twice at intervals of 15 to 20 minutes (Benitz & Tatro, 1988; Giang & McBride, 1988).

c. RECURRING SEIZURES: If seizures cannot be controlled with diazepam or recur, give phenobarbital.
d. PHENOBARBITAL

(1) SERUM LEVEL MONITORING: Monitor serum levels over next 12 to 24 hours for maintenance of therapeutic levels (15 to 25 micrograms per milliliter).
(2) ADULT PHENOBARBITAL LOADING DOSE: 600 to 1200 milligrams of phenobarbital intravenously initially (10 to 20 milligrams per kilogram) diluted in 60 milliliters of 0.9 percent saline given at 25 to 50 milligrams per minute.
(3) ADULT PHENOBARBITAL MAINTENANCE DOSE: Additional doses of 120 to 240 milligrams may be given every 20 minutes.
(4) MAXIMUM SAFE ADULT PHENOBARBITAL DOSE: No maximum safe dose has been established. Patients in status epilepticus have received as much as 100 milligrams/minute until seizure control was achieved or a total dose of 10 milligrams/kilogram.
(5) PEDIATRIC PHENOBARBITAL LOADING DOSE: 15 to 20 milligrams per kilogram of phenobarbital intravenously at a rate of 25 to 50 milligrams per minute.
(6) PEDIATRIC PHENOBARBITAL MAINTENANCE DOSE: Repeat doses of 5 to 10 milligrams per kilogram may be given every 20 minutes.
(7) MAXIMUM SAFE PEDIATRIC PHENOBARBITAL DOSE: No maximum safe dose has been established. Children in status epilepticus have received doses of 30 to 120 milligrams/kilogram within 24 hours. Vasopressors and mechanical ventilation were needed in some patients receiving these doses.
(8) INDICATIONS FOR INTUBATION: Intubation should be considered after total doses of greater than 20 milligrams/kilogram.
(9) NEONATAL PHENOBARBITAL LOADING DOSE: 20 to 30 milligrams/kilogram intravenously at a rate of no more than 1 milligram/kilogram per minute in patients with no preexisting phenobarbital serum levels.
(10) NEONATAL PHENOBARBITAL MAINTENANCE DOSE: Repeat doses of 2.5 milligrams/kilogram every 12 hours may be given; adjust dosage to maintain serum levels of 20 to 40 micrograms/milliliter.
(11) MAXIMUM SAFE NEONATAL PHENOBARBITAL DOSE: Doses of up to 20 milligrams/kilogram/minute up to a total of 30 milligrams/kilogram have been tolerated in neonates.
(12) CAUTIONS: Adequacy of ventilation must be continuously monitored in children and adults. Intubation may be necessary with increased doses.

5. CYPROHEPTADINE

a. Cyproheptadine is a non-specific 5-HT antagonist that has been shown to block development of serotonin syndrome in animals (Sternbach, 1991). Cyproheptadine has been used in the treatment of serotonin syndrome (Mills, 1997; Goldberg & Huk, 1992). There are no controlled human trials substantiating its efficacy.
b. ADULT - 4 to 8 milligrams orally repeated every 1 to 4 hours until therapeutic response is observed or maximum of 32 milligrams administered (Mills, 1997).
c. CHILD - 0.25 milligram/kilogram/day divided every 6 hours, maximum dose 12 milligrams/day (Mills, 1997).

6. NITROGLYCERIN

a. In theory nitroglycerin may help alleviate the serotonin syndrome through nitric oxide mediated downregulation of serotonin. It has been used in human cases with apparent benefit (Brown et al, 1996). There are no human trials substantiating its efficacy
b. ADULT - Begin continuous infusion at 5 micrograms/minute and titrate to desired effect.
c. CHILD - Begin infusion at 0.25 to 0.5 microgram/kilogram/minute and titrate to desired effect.

7. PROPRANOLOL

a. Propranolol is a 5-HT1A receptor antagonist (Sternbach, 1991). Propranolol has been used in human cases of serotonin syndrome with apparent benefit (Guze & Baxter, 1986; Dursun et al, 1997). There are no controlled human trials substantiating its efficacy.
b. PROPRANOLOL/ADULT DOSE

(1) 1 milligram/dose intravenously, administered no faster than 1 milligram/minute repeated every 2 to 5 minutes until desired response is seen or a maximum of 5 milligrams has been given.

c. PROPRANOLOL/PEDIATRIC DOSE

(1) 0.01 to 0.1 milligram/kilogram/dose over 10 minutes. Maximum 1 milligram/dose (Benitz & Tatro, 1988).

8. CHLORPROMAZINE -

a. Chlorpromazine is a 5-HT2 receptor antagonist that has been used to treat cases of serotonin syndrome (Graham, 1997; Gillman, 1996). Controlled human trial documenting its efficacy are lacking.
b. ADULT - 25 to 100 milligrams intramuscularly repeated in one hour if necessary.
c. CHILD - 0.5 to 1 milligram/kilogram repeated as needed every 6 to 12 hours not to exceed 2 milligrams/kilogram/day.

9. OTHER

a. Other agents which have been used to treat serotonin syndrome include methysergide and mirtazapine (Mills, 1997; Hoes, 1996).

10. NOT RECOMMENDED

a. BROMOCRIPTINE - Is used in the treatment of neuroleptic malignant syndrome but is NOT RECOMMENDED in the treatment of serotonin syndrome as it has serotonergic effects (Gillman, 1997). In one case the use of bromocriptine was associated with a fatal outcome (Kline et al, 1989).

6.11 ENHANCED ELIMINATION

A. HEMODIALYSIS

1. Based on its pharmacokinetics, hemodialysis may NOT be of utility following citalopram overdose.

7.0 RANGE OF TOXICITY

7.1 SUMMARY

A. Ingestion of less than 600 milligrams in adults generally results in mild effects. Seizures have developed following overdoses which have exceeded 600 mg of citalopram. Five non-fatal cases of citalopram overdose (up to 5200 mg) resulted in seizures developing in 4 cases and all (five cases) had QT prolongation, sinus tachycardia and inferolateral repolarization disturbances.
B. LACK OF EFFECT - Doses as high as 2000 mg have been taken without observable cardiovascular abnormalities.

7.2 THERAPEUTIC DOSE

7.2.1 ADULT

A. DISEASE STATE

1. DEPRESSION - The usual starting dose in clinical studies has been 20 or 40 milligrams orally once daily and can be titrated to 60 milligrams daily after the first two weeks (Sweetman, 2000). For some patients who experience anxiety or insomnia, a benzodiazepine has been coadministered (Milne & Goa, 1991).

a. Doses as high as 80 milligrams daily have been given for depression (de Wilde et al, 1985).
b. ELDERLY - Elderly patients should receive an initial dose of 20 milligrams/day; up to a maximum of 40 milligrams/day (Sweetman, 2000).

2. PANIC DISORDER with or without agoraphobia - Initial dose - 10 milligrams daily by mouth; increase to 20 milligrams daily after one week to a maximum of 60 milligrams daily (Sweetman, 2000).
3. DIABETIC NEUROPATHY - Oral doses of 40 milligrams daily have been used in the treatment of diabetic neuropathy (Sindrup et al, 1992).
4. POST-STROKE CRYING - Oral doses of 20 milligrams daily have been given in patients with post-stroke crying or depression under the age of 66 years; older patients have been given 10 milligrams daily (Andersen et al, 1993).
5. IMPAIRED RENAL FUNCTION - At the time of this review, no dosing recommendations can be made based on a lack of data (Milne & Goa, 1991).
6. IMPAIRED HEPATIC FUNCTION - Since citalopram is metabolized in the liver (Milne & Goa, 1991), a suggested maximum dose of 40 milligrams/day is recommended in patients with hepatic dysfunction (Sweetman, 2000).

7.3 MINIMUM LETHAL EXPOSURE

A. ADULT

1. CASE REPORT - A 53-year-old female died following a probable overdose of 840 milligrams of citalopram; coingestants included diazepam (0.1 microgram/gram). At necropsy, citalopram concentration was 6.1 micrograms/gram femoral vein blood (Ostrom et al, 1996).
2. CASE REPORT - A 56-year-old male died following an intentional ingestion of 3920 milligrams of citalopram (equivalent to two 100-tablet bottles); no other coingestants were found on necropsy (Ostrom et al, 1996; Glassman, 1997).

B. ACUTE

1. LDLo - (ORAL) HUMAN, Male: 56 mg/kg (RTECS, 2000)

7.4 MAXIMUM TOLERATED EXPOSURE

A. ADULT

1. CASE SERIES - In a series of 108 patients with citalopram overdose, patients who ingested less than 600 milligrams (n=41) developed mild effects (nausea, dizziness, tachycardia, tremor, drowsiness, somnolence). Doses of 600 milligrams to 1.9 grams were associated with seizures in 6 of 34 patients (18%). Seizures developed in 9 of 19 patients (47%) who ingested 1.9 to 5.2 grams (Personne et al, 1997).
2. Seizures have developed following overdoses which have exceeded 600 mg of citalopram. Five non-fatal cases of citalopram overdose (up to 5200 mg) resulted in seizures developing in 4 cases and all (five cases) had QT prolongation, sinus tachycardia and inferolateral repolarization disturbances (Grundemar et al, 1997).
3. LACK OF EFFECT - Doses as high as 2000 mg have been taken without observable cardiovascular abnormalities (as reviewed in Milne & Goa, 1991).
4. CASE REPORT - A 41-year-old male tolerated an estimated overdose of 5200 milligrams of citalopram with transient effects of seizures, metabolic acidosis, hypotension for 1 hour, and ECG changes (QTc prolongation and sinus tachycardia); no permanent sequelae was reported (Grundemar et al, 1997).