Drugs and Dosages in to the mind and beyond

Drugs and dosages

1. Drugs and Dosages Roxanne Jeen L. Fornolles, MD 1 year Pediatrics Resident

2. Objectives Standards of Medication Administration Overview of Prescription writing Common Drugs used in Pediatrics Prescribing Medications in Pediatrics

3. Standards of Medication Administration/Prescription Six Rights of Medication Administration Right Medication Right Dose Right patient Right route Right time Right documentation

4. Prescription Writing Common Household Measures and Equivalents Household Measures Metric Equivalent Apothecary Equivalent 1 drop 1/20 ml (0.05ml) 1 minim 1 teaspoonful 5 ml 1 dram 1 tablespoonful 15 ml ½ fluid oz 1 glassful 250 ml 8 fluid oz

5. Common Abbreviations Used Abbrevation Meaning AC Before meals BID Twice a day GM. or gm. Gram gr. Grain gtt. Drop h.s. At bedtime (hour to sleep) OD Everyday Abbrevation Meaning PC After meals PRN Whenever there is a need QH Every hour QID 4 times a day QS As much as required TID 3 times a day STAT Immediately

6. Abbreviation Meaning u units mcg microgram g gram PO Per orem PR Per rectum IV Intravenous IM Intramuscular ID Intradermal SC Subcutaneous SL Sublingual Abbreviation Meaning syr syrup MDI Metered dose inhaler DPI Dry powder inhaler LD Loading dose MD Maintenance dose Max Maximum dose ER Extended release Supp Suppository

7. Superscription Inscription Subscription Signa Prescriber’s data

8. Common Drugs Used in Pediatrics Amikacin Dose: 15-22.5 mkDay IV/IM q8h (Harriet Lane 21st edition) Preparations: 50mg/amp 125mg/amp 250mg/amp Antimicrobials

9. Common Drugs Used in Pediatrics Side effects: Ototoxicity, Nephrotoxicity and Neuromucular blockade Source: Neofax 2020

10. Drug Dose Preparations Remarks Amoxicillin Neonate–≤ 3 mo: 20–30 mg/kg/24 hr ÷ Q12 hr PO Child: Standard dose: 25–50 mg/kg/24 hr ÷ Q8–12 hr PO High dose (resistant Streptococcus pneumoniae: 80–90 mg/kg/24 hr ÷ Q8–12 hr PO Tonsillitis/pharyngitis (S. pyogenes): 50 mg/kg/24 hr ÷ Q12 hr PO × 10 days; max. dose: 1 g/24 hr PAPP 2016 PCAP: 40-50 mg/kg/day, maximum dose of 1500 mg/day in 3 divided doses (low antibiotic resistance). 90 mg/kg/day in areas with proven high amoxicillin resistance Preparations 100mg/ml 250mg/5ml Immediate hypersensitivity, rash, seizures Amoxicillin-Clavulanic acid Infant 1-<3 mos: 30 mg/kg/24 hr ÷ Q12 hr PO (recommended dosage form is 125 mg/5 mL suspension) Child ≥ 3 mo (for non–high-dose amoxicillin regimens, use adult dosage if ≥ 40 kg): TID dosing 20–40 mg/kg/24 hr ÷ Q8 hr PO BID dosing (see remarks): 25–45 mg/kg/24 hr ÷ Q12 hr PO Preparations 312.5mg/5ml 457mg/5ml 625mg/tab Rash and diarrhea

11. Drug Dose Preparations Ampicillin Neonate: Usual dose is 25-50 mkd by IV slow push or IM Mild-moderate infection: 100-200mkD IV/IM Q6H Severe infection: 200-400mkD IV/IM Q4H/Q6H 250mg vial 500 mg vial 1 gram vial

12. Drug Dose Preparations Remarks Ampicillin-Sulbactam Infant>=1month: Mild/moderate infections: 100–150 mg/kg/24 hr ÷ Q6 hr IM/IV Meningitis/severe infections: 200–300 mg/kg/24 hr ÷ Q6 hr IM/IV Child (see remarks): Mild/moderate infections: 100–200 mg/kg/24 hr ÷ Q6 hr IM/IV; max. dose: 1 g ampicillin/dose Meningitis/severe infections: 200–400 mg/kg/24 hr ÷ Q4–6 hr IM/IV 375 mg/vial 750 mg/vial 1.5 g/vial 750 mg/tab Dose is based on Ampicillin component Immediate hypersensitivity, rash, seizure Azithromycin Pharyngitis/tonsillitis (2–15 yr): 12 mg/kg/24 hr PO once daily × 5 days (max. dose: 500 mg/24 hr) Acute sinusitis (≥ 6 mo): 10 mg/kg/dose (max. dose: 500 mg) PO once daily × 3 days. Pertussis: Infant < 6 mo: 10 mg/kg/dose PO once daily × 5 days ≥6 mo: 10 mg/kg/dose (max. dose: 500 mg) PO × 1, followed by 5 mg/kg/ (max. dose: 250 mg) PO once daily on days 2–5. PAPP 2016 PCAP: 10 mg/kg/day OD for 3 days, or 10 mg/kg/day at day 1 then 5 mg/ kg/day for day 2 to 5, maximum dose of 500 mg/day 500mg/vial 200mg/5ml susp 500mg tab 250mg tab Contraindicated in hypersensitivity to macrolides and history of cholestatic jaundice/hepatic dysfunction associated with prior use. Cefalexin Infant and child: Mild/moderate infection: 25–50 mg/kg/24 hr PO ÷ Q6 hr; max. dose: 2 g/24 hr. Less frequent dosing (Q8–12 hr) may be used for uncomplicated infections. Severe infection: 75–100 mg/kg/24 hr PO ÷ Q6 hr; max. dose: 4 g/24 hr Streptococcal pharyngitis and skin infections: 25–50 mg/kg/24 hr PO ÷ Q6–12 hr. Total daily dose may be divided Q12 hr for streptococcal pharyngitis (>1 yr). UTI: 50–100 mg/kg/24 hr PO ÷ Q6 hr 500 mg/cap 250mg/cap 250mg/5ml oral sus 100mg/ml oral drops S/E: GI Discomfort

13. Drug Dose Preparations Remarks Cefaclor Child aged >1–mo-old (use regular-release dosage forms): 20–40 mg/kg/24 hr PO ÷ Q8 hr; max. dose: 1 g/24 hr Q12 hr dosage interval option for pharyngitis: 20 mg/kg/24 hr; max. dose: 1 g/24 hr 50mg/ml drops 125mg/5ml susp 250mg/5ml susp 500mg/cap Side effects include elevated LFTs, bone marrow suppression, and moniliasis Cefuroxime IV/IM: 75-100 mkD every 8 hours PO: 20-30 mkD Q12H IV/IM Prep: 250 mg/vial, 750 mg/vial, 1.5 g/vial PO: 500mg/tab, 125mg/5 sus, 250/5 sus S/E: GI discomfort Cefotaxime Usual dose: 100-200mkD IV/IM Q6/Q8 Meningitic dose: 200 mkD IV/IM Q6H Disseminated Gonococcal Infections and Gonococcal scalp abscesses: 25 mkd IV or IM Q12H for 7 days with a duration of 10-14 days if meningitis is documented Meningitis 0-7 days of age: 100-150 mkd IV divided q8-12H. Consider smaller doses and onger interval for VLBW (Less than 2kg) 8 days of older: 150-200 mkd IV divided q6-8H. Consider smaller doses and onger interval for VLBW (Less than 2kg) 250mg/vial 500mg/vial 1g/vial Allergy Neutropenia Thrombocytopenia Eosinophilia

14. Ceftazidime Usual dose 90-150mkD IV/IM Q8H Meningitic dose 150mkD IV/IM Q8H 250 mg vial 500 mg vial 1 gram vial 2 gram vial Rash

15. Drug Dose Preparations Remarks Ceftriaxone Usual dose: 50-75mkD IV/IM Q12-Q24H Meningitic dose/Penicillin-resistant pneumococci 100mkD IV/IM Q12H 250mg vial 500 mg vial 1 gram vial Max dose: 2 grm/day S/E: Rash, pain over injection site, diarrhea, jaundice cholelithiasis, GB sludging Cefepime Usual dose: 100mkD IV/IM Q12H Meningitic, neutropenia, serious infection 150mkD IV/IM Q8H Term and preterm neonates greater than 28 days of age: 50mkd IV Q12H Term and preterm neonates 28 days of age and younger: 30 mkd IV Q12H Meningitis and severe infections due to P. aeruginosa and Enterobacter spp.: 50mkd IV Q12H 500mg vial 1 gram vial S/E: GI Discomfort, thrombophlebitis Clarithromycin 15 mkD PO Q12H 250mg/5ml 125mg/5ml 500 mg S/E: Diarrhea, abdominal pain Clindamycin IV/IM: 25-40 mkD Q6H-Q8H PO: 10-30mkD Q6-Q8H Bacterial endocarditis proph: 20mkd PO 1 hr before procedure IV: 150 mg/ml amp, 150mg/2 ml amp PO: 75 mg/cap, 150mg/cap, 300mg/cap, 75mg/5ml S/E: Diarrhea, rash, pseudomembranous colitis, Steven-Johnson Syndrome, thrombocytopenia Chloramphenicol Usual dose: 50-75mkD IV or PO Q6H Meningitic dose: 75-100mkd IV Q6H 250mg/cap, 500mg/cap, 125mg/5ml syr, 1 gram/vial S/E:Bone marrow suppression, Gray baby syndrome, Use caution in patients with G6PD, Renal of Hepatic dysfunction

16. Drug Dose Preparations Remarks Cloxacillin Mild-moderate infection: 12.5-50 mkD PO Q6H Severe: 50-100 mkD PO Q6H 500mg/cap 125mg/5 ml suspension 250mg/5ml suspension S/E: Nausea, vomiting, diarrhea Erythromycin 30-50 mkD PO Q6-Q8H Rheumatic fever prophylaxis: 500mkD PO Q12H Pertussis: 50mkD PO Q6H X 14 days 250 mg tab 500 mg tab 100 mg/ml drops 100 mg/2.5 ml 125 mg/5 ml 200 mg/5ml 250 mg/5ml 400 mg/5ml S/E: Nausea, vomiting, abdominal cramps, Hypertrophic pyloric stenosis in neonates Gentamicin 7.5 mkD IV/IM Q8H 40 mg/ml Ototoxicity and Nephrotoxicity

17. Drug Dose Preparations Remarks Meropenem Meningitis (1–3 mo, IV; recommendation from 2004 IDSA meningitis practice guidelines): 40 mg/ kg/dose Q8 hr Infant (≥3 mo), child, and adolescent (IV): Meningitis, severe infections, cystic fibrosis pulmonary exacerbations: 40 mg/kg/dose (max. 2 g/ dose) Q8 hr Complicated skin and skin structure infection: 10 mg/kg/dose (max. dose: 500 mg/dose) Q8 hr. If Pseudomonas aeruginosa is suspected or confirmed, use 20 mg/kg/dose (max. dose: 1 g/dose) Q8 hr. Intraabdominal and mild/moderate infections and fever/neutropenia empiric therapy: 20 mg/kg/ dose (max. dose: 1 g/dose) Q8 hr 500mg/vial 1 gram/vial S/E: Diarrhea, rash, Nausea, headache and pain at the injection site.

18. Drug Dose Preparations Remarks Metronidazole Amebiasis: Child: 35–50 mg/kg/24 hr PO ÷ TID × 10 days Anaerobic infection: Infant/child/adolescent: PO: 30–50 mg/kg/24 hr ÷ Q8 hr; max. dose: 2250 mg/24 hr IV: 22.5–40 mg/kg/24 hr ÷ Q8 hr; max. dose: 1500 mg/24 hr. Giardiasis: Child: 15 mg/kg/24 hr PO ÷ TID × 5–7 days; max. dose: 750 mg/24 hr Trichomoniasis: Treat sexual contacts Child: 15 mg/kg/24 hr PO ÷ TID × 7 days; max. dose: 2000 mg/24 hr Adolescent/adult: 2 g PO × 1, or 250 mg PO TID, or 375 mg PO BID × 7 days Clostridium difficile infection (IV may be less efficacious): Child: 30 mg/kg/24 hr ÷ Q6 hr PO/IV × 7–14 days; max. dose: 2000 mg/24 hr Helicobacter pylori infection (use in combination with amoxicillin and acid suppressing agent with/ without clarithromycin): Child: 20 mg/kg/24 hr (max. dose: 1000 mg/24 hr) ÷ BID PO × 10–14 days Adult: 250–500 mg QID (QAC and QHS) PO × 10–14 days 500mg/tab 125mg/5ml 500mg/vial S/E: Nausea, diarrhea, dry mouth, leukopenia, metallic taste disulfiram-type reaction with alcohol ingestion Oxacillin 100-200 mkD IV/IM Q4-Q6H 500mg vial S/E: Rash, GI Discomfort

19. Oxacillin Usual dosage: 25 mkd IV over at least 10 mins Meningitis: 50 mkd IV over at least 10 mins

20. Drug Dose Preparations Remarks Piperacillin-Tazobactam <6 months: 150-300 mkD IV Q6/Q8H >6 months: 300-400 mkD IV Q6/Q8H 2.25 gms/vial 4.45 gms/vial S/E: Rash, diarrhea, headache, fever, thrombophlebitis

21. Drug Dose Preparations Remarks Vancomycin Mild to moderate infection: 40-45 mkD IV Q6/Q8H Severe infection: 45-60 mkD IV Q6/Q8H 500mg vial 1 gm vial S/E: Red Man Syndrome, Ototoxicity, Nephrotoxicity

22. Antituberculous Agents Drug Dose Preparations Remarks Isoniazid 10 (10-15 mkD PO OD) 300 mg/tab 200mg H/10 mg Pyridoxine/5 ml syrup 200mg H/12 mg Pyridoxine/5ml syrup 200mg H/20 mg Pyridoxine/5ml syrup WOF: Peripheral neuropathy, hepatic side effects Supplemental pyridoxine (1-2 mkD is recommended) Rifampicin 15 (10-20 mkD PO OD) Prophylaxis for N. Meningitis 20 mkD PO Q12H X 2 days 200mg/5ml syrup WOF: GI Irritation, Hepatitis, allergy,ataxia, blood dyscrasia, hyperuricemia Causes red discoloration of urine, saliva and tears Pyrazinamide 30 (20-40 mkD PO OD) 250mg/5ml syrup WOF: Hepatotoxicity, rash, hyperuricemia, arthralgia, fever, acne Ethambutol 20 (15-25 mkD PO OD) 400 mg/tab WOF:Optic neuritis Streptomycin 30 (20-40 mkD IM OD) 1 gm/vial WOF: Ototoxicity, Nephrotoxicity, Serum sickness

23. Antifungal Medications Drug Dose Preparations Remarks Amphotericin B Initial dose: 0.5-1 mkD Maintenance dose: 0.5-1 mkD IV OD or 1.5 mkd every other day 50 mg vial WOF: Fever, chills, headache, hypotension, vomiting, hypercalciuria Fluconazole Oropharyngeal Candidiasis: LD 6 mkd IV/PO, MD 3 mkD IV/PO OD Esophageal candidiasis: LD 12 mkd IV/PO, 6 mkD IV/PO OD Cryptococcal meningitis or invasive systemic candidiasis: LD 12 mkd IV/PO MD 6-12 mkD IV/PO OD 50 mg/cap 150 mg/cap 200 mg/cap 200 mg vial WOF: Nausea, headache, vomiting, diarrhea, abdominal pain, hepatitis

24. Antiviral Medications Drug Dose Preparations Remarks Acyclovir IV for HSV encephalitis: 3 mos<12 yrs: 60 mkD Q8 X 14-21 days >=12 yrs: 30 mkD Q8H X 14-21 days IV for Varicella: >=2yo: 30 mkD Q8H or 1500 mg/m2/day q8hx 7-10 days PO for Varicella >=2 yo: 20 mkd Q6h x 5 days 250 mg vial 200 mg/tab 400 mg/tab 800 mg/tab 200mg/5 ml syrup WOF: renal impairment Oseltamivir 3-8 months old: 3 mg/kg per dose twice daily x 5 days 9-11 months old: 3.5 mg/kg per dose twice daily x 5 days >12 months old: weight 15-23 kg at 45 mg twice daily x 5 days >23-40 kg at 60 mg twice daily x 5 days >40 kg at 75 mg twice daily x 5 days doses to be started within 48 hours of onset of influenza-like symptoms. 75 mg/cap S/E: Nausea and Vomiting

25. Antipyretics Drug Dose Preparations Remarks Aspirin Analgesic/Antipyretic: 10-15 mkd PO Q4-Q6 Anti-inflammatory: 60-100 mkD PO Q6/Q8h Kawasaki Disease: 30-50 mkD or 80-100mkD Q6h PO until the patient is afebrile for at least 48 hrs, 3-5 mkD PO OD 80 mg/tab S/E: GI Upset, liver toxicity, decreased platelet aggregation Do not use in <16 yrs old for Varicella or Flu like Symptoms due to risk of Reye Syndrome Ibuprofen 5-10 mkd PO Q6/Q8 200 mg/tab 300 mg/tab 400 mg/tab 200 mg/5ml S/E: GI discomfort, rashes, hypertension, ocular problems, anemia Paracetamol 10-15 mkd PO/PR Q4 to Q6H <50 kg: 15 mkd Q6H or 12.5 mkd IV Q4 >50 kg, adolescents, and adults: 500-1000 mg Q6H or 650 mg IV Q4H 500mg/tab 100mg/ml drops 120mg/5ml 250mg/5ml 150mg/amp 300mg/amp S/E: Nausea, vomiting, constipation, pruritus, agitation, atelectasis, hepatotoxicity when used with Carbamazepine, Phenytoin or chronic alcohol use

26. Prescribing Medications Example: You want to prescribe to a 5 yo child weighing 19 kg with oral Cefuroxime for 7 days. The available preparation is 250mg/5ml 60ml bottle. Recommended dose: Cefuroxime PO 20-30 mkD Q12H Desired dose: 25 mkD Dose Weight x Desired dosage/ Preparation = 19 kg x 25 mkD/ (250/5) = 475 X 5 ml / 250 mg = 2375/250mg =9.5ml /2 (given twice daily) =4.75 ml ≈ 5ml Dispense Dispense number= 5ml x 2 x 7 days =70 ml = 70 ml/60ml 1.16 bottles ≈ 2 bottles Sig.: Give 5 ml twice daily for 7 days (every 8am and 8pm) Actual dose 5ml x 2 x 250mg/ 5ml/19kg = 26.3 mkD

27. Exercise Compute: An 8 yo child weighing 26 kg came in with history of cough for 3 days and fever for 1 day. You diagnosed the patient with PCAP-B. You want to prescribe Clarithromycin for 7 days and Paracetamol PRN for fever. Available stocks: Clarithromycin 125mg/5ml 50ml bottle and Paracetamol 250mg/5ml 60ml bottle. Recommended dose of Clarithromycin 15mkD PO Q12H and for Paracetamol 10-15mkd Q4h PRN for fever

28. Exercise Compute: An 8 yo child weighing 26 kg came in with history of cough for 3 days and fever for 1 day. You diagnosed the patient with PCAP-B. You want to prescribe Clarithromycin for 7 days and Paracetamol PRN for fever. Available stocks: Clarithromycin 125mg/5ml 50ml bottle and Paracetamol 250mg/5ml 60ml bottle. Recommended dose of Clarithromycin 15mkD PO Q12H and for Paracetamol 10-15mkd Q4h PRN for fever Clarithromycin Dose Weight x Desired dosage/ Preparation = 26 kg x 15mkD (125mg/5ml) =390 ml x 5ml /125 mg = 1950 ml / 125 mg = 15.6 ml /2 = 7.8 ml ≈ 8ml Dispense 8ml x 2 x 7 days =112 ml = 112 ml/50ml = 2.24 bottles ≈ 3 bottles Sig.: Give 8ml twice daily for 7 days (every 8am and 8pm) Actual dose 8ml x 2 x 125mg/5ml/26kg =15.4 mkD

29. Exercise A 2-day old term neonate at the nursery (BS 38 wks, BW 3200 grms) was noted to have poor suck and had onset of 1 episode of vomiting. CBC was taken showing normal results and CRP was elevated at 10 mg/L (NV<6.45 mg/L), blood culture taken with pending results. What antibiotics should you start: What is the RD? What is your AD?

30. Exercise Ampicillin Dose 3.2 kg x 25= 80 mg IVTT Q12H 3.2 kg x 50= 160 mg IVTT Q12H 250 mg IVTT Q12H AD 25mkd / 50mkD AD 50mkd / 100mkD AD 78 mkd / 156 mkD

31. Amikacin Side effects: Ototoxicity, Nephrotoxicity and Neuromucular blockade Source: Neofax 2020

32. Exercise Amikacin Dose 3.2 kg x 12= 38 mg IVTT Q24H AD 11.8 mkd/ 12mkd

33. Exercise: 1 year old, 10.5 kg CC: Cough and Fever Dx: PCAP-B Meds: Amoxicillin, Paracetamol 2 year old, 13 kg CC: Fever, Cough x 3 Days Dx: PCAP-A Meds: Co-Amox, Paracetamol 3 year old, 17 kg CC: Cold, Fever x 3 days Dx: Viral Pneumonia Meds: Oseltamivir, Phenylephrine 4 year old, 19 kg CC: Infected wound, Fever Dx: Cellulitis Meds: Cloxacillin, Ibuprofen 5 year old, 24 kg CC: Cough and Colds, Fever x 3days Dx: PCAP-C Meds: Cefuroxime, Paracetamol 6. Newborn , 3.5 kg CC: poor suck, vomiting Dx: Neonatal Sepsis Meds: Ampicillin, Amikacin 7. 7 months, 8.6 kg CC: Cough and Fever x 1 week Dx: PCAP-B Meds: Cefuroxime IV, Paracetamol 8. 8 year old, 26kg CC: Swollen Eyes, Fever Dx: Preseptal Cellulitis Meds: Clindamycin IV, Paracetamol 9. 9 year old, 26kg CC: LBM x 3days Dx: Intestinal Amoebiasis Meds: Metronidazole PO, Probiotics

34. Thank you