Question

4. Calculate the following dosage. Use labels where provided. Dosage: Order: Lithium citrate 0.6 g p.o. b.i.d. Available: 500 mL NDC 0054- 3527-63 LITHIUM Citrate Syrup USP 8 mEq per 5 mL Each 5 ml contains: 8 mEq of LITHIUM ION (Equivalent to 300 mg of Lithium Carbonate per 5 ml), Alcohol 0.3% VW SUGAR FREE FOR ORAL ADMINISTRATION ONLY Usual Adult Dose: 5 or 10 ml, 1 of 2 teaspoonfuls. (8 of 16 mEq of Lithium) three times a day Dispense in tight container as defined in the USPINE Store Controlled Room Temperature 15-30 C (59 -86°F) See Package Insert for Complete Prescribing information Caution: Federal law prohibits dispensing without prescription S0054-3527-63 E per 5 ml 1530 (5986F) LITHIUM CITRATE SYRUP USD. Store at Control Room Tempera LOT EXP. 8 Roxane NSN 6505 01-168-0537 4121000 033 RLI, 1993

Answer 1

ANSWER.

4) Calculation of dosage.

       Formula

        Volume of drug required = Desired dose/Dose in hand * Quantity.

   Here

        Desired dose (D) = 600 mg (0.6 g)

        Dose in hand (H) = 300 mg.(300 mg of lithium per 5 ml as per label).

           Quantity (Q) = 5 ml

As per above formula

       Volume(ml) of drug required = D/H * Q

                                                     = 600/300 * 5

                                                     = 2 * 5

                                                     = 10 ml.