Pediatric Hypertension and Medication Management

Medication Administration and Counseling

Proper administration of medication often involves dissolving $100\,mg$ tablets in $50\,ml$ of water or apple juice. Patients should use an amber oral syringe to withdraw the prescribed dose. The dose should be emptied into a glass or plastic cup, mixed with at least $2$ ounces of water or orange juice, and consumed immediately. Important counseling points include wearing sunscreen and protective clothing due to increased skin cancer risk, monitoring for infections (headache, fever), and watching for hypertension. Medication stored at room temperature between $20$ to $25^\circ C$ or refrigerated must be protected from light. If a once-weekly Thursday schedule is used, patients must skip folic acid on that day due to a drug interaction. Products should be used within one month of opening.

Clinical Case Study: Pediatric Hypertension

Patient WS is an 11-year-old African American female weighing $42\,kg$ ($50^{th}$ percentile) and measuring $59$ inches ($50^{th}$ percentile). She exhibits a blood pressure of $124/82$. Normotensive status is defined as systolic or diastolic pressure less than the $90^{th}$ percentile. Prehypertension is categorized as the $90^{th}$ to $95^{th}$ percentile or greater than $120/80$. Stage 1 hypertension is the $95^{th}$ to $99^{th}$ percentile plus $5$. For WS, the stimulant Concerta ($36\,mg$ by mouth every morning) may contribute to her elevated readings. Recommended workup includes assessing cardiovascular risk factors like triglycerides, family history, electrolytes, and creatinine. Non-pharmacological management for this age group includes limiting sodium intake to $2,200\,mg$ per day and performing $60$ minutes of physical activity weekly.

Renal Function and Pharmacotherapy

Renal function is assessed using the bedside Schwartz equation: $CrCl = \frac{k \times \text{length}}{\text{serum creatinine}}$. For an 11-year-old girl, the constant $k$ is $0.43$. WS has a serum creatinine of $0.85\,mg/dL$ (normal range for her age is $0.42$ to $0.71\,mg/dL$). Converting her height of $59$ inches to $149.86\,cm$ results in a calculated creatinine clearance of approximately $73\,ml/min/1.73m^2$. When her blood pressure reached $132/88$, the condition progressed to Stage 1 hypertension. First-line treatments for pediatric patients include amlodipine (starting at $2.5\,mg$), losartan ($25\,mg$ for her weight), or lisinopril ($0.07\,mg/kg$, roughly $2.5\,mg$ based on tablet size).

Pediatric Fluid Calculations

Maintenance fluid rates are determined by the Holiday-Segar method. For a 6-year-old weighing $40\,lbs$ ($18\,kg$), the calculation is $4\,ml/kg/hr$ for the first $10\,kg$ ($40\,ml$) plus $2\,ml/kg/hr$ for the remaining $8\,kg$ ($16\,ml$), totaling $56\,ml/hr$. Recommended fluids often include Lactated Ringer's. For infants, fluid intake may be calculated by volume: an infant taking $8$ ounces every $4$ hours consumes $1,440\,ml/day$. This equates to $160\,ml/kg/day$, which may be considered aggressive. Glucose infusion rates (GIR) are calculated in $mg/kg/min$, noting that to convert percent to $mg/ml$, one should multiply the percentage by $10$.

Questions & Discussion

Question: A student in Orlando asked if Stage 1 hypertension criteria include a range of $130/80$ to $139/89$ for adolescents versus children, noting $WS$ had an $82$ diastolic. Response: The instructor clarified that Stage 1 is generally $130$ to greater than $89$, but noted the slide details should be checked for exact pediatric age cut-offs. For the current case, she was considered prehypertensive as she was not yet greater than $5$ over the $95^{th}$ percentile.

Question: What should a pharmacist recommend if a patient's hypertension is potentially caused by ADHD medication like Concerta? Response: This requires a risk-benefit analysis. If the patient is well-controlled and focusing in school on Concerta, the provider may choose to add an antihypertensive rather than remove the stimulant, depending on the severity of the blood pressure readings.