Pharmacokinetics of intravenous and rectal ketoprofen in young children

Efficacy and Safety of NSAIDs in Infants: A Comprehensive Review of the Literature of the Past 20 Years

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in infants, children, and adolescents worldwide; however, despite sufficient evidence of the beneficial effects of NSAIDs in children and adolescents, there is a lack of comprehensive data in infants. The present review summarizes the current knowledge on the safety and efficacy of various NSAIDs used in infants for which data are available, and includes ibuprofen, dexibuprofen, ketoprofen, flurbiprofen, naproxen, diclofenac, ketorolac, indomethacin, niflumic acid, meloxicam, celecoxib, parecoxib, rofecoxib, acetylsalicylic acid, and nimesulide. The efficacy of NSAIDs has been documented for a variety of conditions, such as fever and pain. NSAIDs are also the main pillars of anti-inflammatory treatment, such as in pediatric inflammatory rheumatic diseases. Limited data are available on the safety of most NSAIDs in infants. Adverse drug reactions may be renal, gastrointestinal, hematological, or immunologic. Since NSAIDs are among the most frequently used drugs in the pediatric population, safety and efficacy studies can be performed as part of normal clinical routine, even in young infants. Available data sources, such as (electronic) medical records, should be used for safety and efficacy analyses. On a larger scale, existing data sources, e.g. adverse drug reaction programs/networks, spontaneous national reporting systems, and electronic medical records should be assessed with child-specific methods in order to detect safety signals pertinent to certain pediatric age groups or disease entities. To improve the safety of NSAIDs in infants, treatment needs to be initiated with the lowest age-appropriate or weight-based dose. Duration of treatment and amount of drug used should be regularly evaluated and maximum dose limits and other recommendations by the manufacturer or expert committees should be followed. Treatment for non-chronic conditions such as fever and acute (postoperative) pain should be kept as short as possible. Patients with chronic conditions should be regularly monitored for possible adverse effects of NSAIDs.

Gastrointestinal-resident, shape-changing microdevices extend drug release in vivo

Extended-release gastrointestinal (GI) luminal delivery substantially increases the ease of administration of drugs and consequently the adherence to therapeutic regimens. However, because of clearance by intrinsic GI motility, device gastroretention and extended drug release over a prolonged duration are very challenging. Here, we report that GI parasite-inspired active mechanochemical therapeutic grippers, or theragrippers, can reside within the GI tract of live animals for 24 hours by autonomously latching onto the mucosal tissue. We also observe a notable sixfold increase in the elimination half-life using theragripper-mediated delivery of a model analgesic ketorolac tromethamine. These results provide first-in-class evidence that shape-changing and self-latching microdevices enhance the efficacy of extended drug delivery.

Nonopioid analgesics for perioperative and cardiac surgery pain in children: Current evidence and knowledge gaps

Objective:

The purpose of this review is to present the available literature on the use of nonopioid analgesics such as nonsteroidal anti-inflammatory drugs in postcardiac surgery pediatric patients, mainly to focus on patients <1 year of age, and to provide the foundation for future research.

Materials and Methods:

Published studies that address the use on nonopioid medications for postoperative sedation and analgesia in infants and children undergoing cardiac surgery were identified from online sources. Studies were reviewed by two authors independently to assess the quality of the data as well as the evidence. Due to limited availability of such studies, the review was then expanded to include use in noncardiac procedures as well as to expanded age groups. All studies that met the primary objective were included.

Results/Data Synthesis:

Majority of the studies in the population of interest were related to use of ketorolac. Five studies specifically addressed ketorolac use in cardiac patients. In addition, studies were reviewed for nonopioid analgesia in noncardiac patients and included as a part of the available evidence as in the case of acetaminophen use. Newer agents as well as agents with very limited information were also acknowledged.

Conclusion:

Nonopioid medications appear to show promise for analgesia in infants undergoing cardiac surgery, with ketorolac being the most potent agent as a potential substitute for opioids. These agents demonstrate a reasonable safety profile even in the very young. There continue to be significant gaps in knowledge before their adoption becomes routine. However, gives the awareness regarding short-term and long-term impact of opioid use in this vulnerable population, and studies of such agents are an urgent need.

Continuous Infusion Nonsteroidal Anti-Inflammatory Drugs for Perioperative Pain Management

Purpose:

To review the use of continuous infusion (CI) nonsteroidal anti-inflammatory drugs (NSAIDs) as an alternative modality for pain control in surgical patient populations.

Methods:

A PubMed and MEDLINE search was conducted from 1964 through February 2016 using the following search terms alone or in combinations: continuous, infusion, nonsteroidal anti-inflammatory drug, diclofenac, ibuprofen, indomethacin, ketoprofen, ketorolac, and surgery. All English-language, prospective and retrospective, adult and pediatric studies evaluating intravenous or intramuscular CI NSAIDs for surgical pain were evaluated for inclusion in this review.

Results:

Twenty four prospective and retrospective publications evaluating CI NSAIDs were identified: 12 in abdominal surgery, 7 in orthopedic surgery, and 5 in pediatric surgery. Specific CI NSAIDs utilized included diclofenac, indomethacin, ketoprofen, and ketorolac. Most studies compared the CI NSAID to placebo or an alternative analgesic and evaluated pain control, supplemental opioid use, and related adverse effects. In these surgical populations, CI NSAIDs decreased opioid consumption, alongside provision of adequate pain control. While long-term adverse effects were rarely collected, a decrease in nausea and sedation was often seen with the CI NSAID groups.

Conclusions:

In the abdominal, orthopedic, and pediatric surgical populations, CI NSAIDs represent a feasible alternative modality for perioperative pain control.

Considerations for a Pediatric Biopharmaceutics Classification System (BCS): application to five drugs

It has been advocated that biopharmaceutic risk assessment should be conducted early in pediatric product development and synchronized with the adult product development program. However, we are unaware of efforts to classify drugs into a Biopharmaceutics Classification System (BCS) framework for pediatric patients. The objective was to classify five drugs into a potential BCS. These five drugs were selected since both oral and intravenous pharmacokinetic data were available for each drug, and covered the four BCS classes in adults. Literature searches for each drug were conducted using Medline and applied to classify drugs with respect to solubility and permeability in pediatric subpopulations. Four pediatric subpopulations were considered: neonates, infants, children, and adolescents. Regarding solubility, dose numbers were calculated using a volume for each subpopulation based on body surface area (BSA) relative to 250 ml for a 1.73 m(2) adult. Dose numbers spanned a range of values, depending upon the pediatric dose formula and subpopulation. Regarding permeability, pharmacokinetic literature data required assumptions and decisions about data collection. Using a devised pediatric BCS framework, there was agreement in adult and pediatric BCS class for two drugs, azithromycin (class 3) and ciprofloxacin (class 4). There was discordance for the three drugs that have high adult permeability since all pediatric permeabilities were low: dolasetron (class 3 in pediatric), ketoprofen (class 4 in pediatric), and voriconazole (class 4 in pediatric). A main contribution of this work is the identification of critical factors required for a pediatric BCS.

Rectal route in the 21st Century to treat children

The rectal route can be considered a good alternative to the oral route for the paediatric population because these dosage forms are neither to be swallowed nor need to be taste-masked. Rectal forms can also be administered in an emergency to unconscious or vomiting children. Their manufacturing cost is low with excipients generally regarded as safe. Some new formulation strategies, including mucoadhesive gels and suppositories, were introduced to increase patient acceptability. Even if recent paediatric clinical studies have demonstrated the equivalence of the rectal route with others, in order to enable the use of this promising route for the treatment of children in the 21st Century, some effort should be focused on informing and educating parents and care givers. This review is the first ever to address all the aforementioned items, and to list all drugs used in paediatric rectal forms in literature and marketed products in developed countries.

Factors and Mechanisms for Pharmacokinetic Differences between Pediatric Population and Adults

Many physiologic differences between children and adults may result in age-related changes in pharmacokinetics and pharmacodynamics. Factors such as gastric pH and emptying time, intestinal transit time, immaturity of secretion and activity of bile and pancreatic fluid among other factors determine the oral bioavailability of pediatric and adult populations. Anatomical, physiological and biochemical characteristics in children also affect the bioavailability of other routes of administration. Key factors explaining differences in drug distribution between the pediatric population and adults are membrane permeability, plasma protein binding and total body water. As far as drug metabolism is concerned, important differences have been found in the pediatric population compared with adults both for phase I and phase II metabolic enzymes. Immaturity of glomerular filtration, renal tubular secretion and tubular reabsorption at birth and their maturation determine the different excretion of drugs in the pediatric population compared to adults.

Ketoprofen pharmacokinetics, efficacy, and tolerability in pediatric patients

The NSAID ketoprofen is used widely in the management of inflammatory and musculoskeletal conditions, pain, and fever in children and adults. Pharmacokinetic studies show that drug exposure after a single intravenous dose is similar in children and adults (after dose normalization), and thus similar mg/kg bodyweight dosing may be used in children and adults. Ketoprofen crosses the blood-brain barrier and therefore has the potential to cause central analgesic effects. Ketoprofen has been investigated in children for the treatment of pain and fever, peri- and postoperative pain, and inflammatory pain conditions. The results of four clinical trials in febrile conditions with the oral syrup formulation indicate that ketoprofen is as effective as acetaminophen (paracetamol) and ibuprofen, allowing children to rapidly return to daily activities with improvements in sleep quality and appetite. Studies of ketoprofen in the management of postoperative pain indicate that ketoprofen is a highly effective analgesic when administered perioperatively for a variety of surgical types, by a variety of routes, and whether given preoperatively or postoperatively. For adenoidectomy, intravenous ketoprofen provided superior postoperative analgesic efficacy compared with placebo. Analgesic efficacy was similar with intravenous, intramuscular, or rectal routes of administration, but oral administration just before surgery was inferior to intravenous administration in this setting. In patients undergoing a tonsillectomy, intravenous ketoprofen was superior to intravenous tramadol in terms of the need for postoperative rescue analgesia, but did not remove the need for rescue opioid therapy in these patients. Intravenous ketoprofen had superior postoperative analgesic efficacy to placebo when given as an adjuvant to epidural sufentanil analgesia after major surgery. Oral ketoprofen has shown efficacy in the treatment of juvenile rheumatoid arthritis. Ketoprofen is generally well tolerated in pediatric patients. Most of the adverse events reported are mild and transient, and are similar to those observed with other NSAIDs. Long-term tolerability has not yet been fully established in children, but data from three studies in >900 children indicate that oral ketoprofen is well tolerated when administered for up to 3 weeks after surgery. In conclusion, ketoprofen is effective and well tolerated in children for the control of post-surgical pain and for the control of pain and fever in inflammatory conditions.

Ketoprofen produces modality-specific inhibition of pain behaviors in rats after plantar incision

BACKGROUND

Postoperative pain remains a significant problem despite optimal treatment with current drugs. Nonsteroidal antiinflammatory drugs reduce inflammation and provide analgesia but are associated with adverse side effects.

METHODS

We tested low doses (0.5-5 mg/kg) of parenteral ketoprofen against pain-related behaviors after plantar incision in rats. To further evaluate the potential sites of action of ketoprofen in our model, a novel, sustained-release microparticle formulation of ketoprofen was placed into the wound, and tested for its effects on pain behaviors. Intrathecal ketoprofen (150 microg) was also studied. Plasma samples were assayed for drug concentrations.

RESULTS

We found that low doses of parenterally administered ketoprofen produced a modality-specific effect on pain behaviors; guarding after incision was decreased, whereas no inhibition of exaggerated responses to heat or mechanical stimuli was evident. Very low doses, 0.5 mg/kg, could produce inhibition of guarding. The locally applied sustained-release ketoprofen-eluting microparticles and intrathecally administered ketoprofen also produced a modality-specific effect on pain behaviors after incision, inhibiting only guarding. Plasma levels of ketoprofen after parenteral or local administration were in the range of therapeutic blood levels in postoperative patients.

CONCLUSIONS

This study demonstrates that ketoprofen is an effective analgesic for nonevoked guarding in rats after plantar incision. There was no effect on mechanical or heat responses, which highlights the importance of multiple-modality testing of pain behaviors for drug evaluation. We found efficacy at doses used clinically in postoperative patients.

Antipyretic effect of ketoprofen

OBJECTIVE

The aim of this study was to investigate the efficacy and side effect profile of ketoprofen as well as compliance with respect to the taste of the drug and compare these parameters with those of acetaminophen and ibuprofen.

METHODS

A total of 301 patients between 1-14 years of age who applied to emergency rooms of three medical centers with the complaint of fever that required antipyretic therapy were included in the study. Fever was measured with the aid of a tympanic thermometer (Braun Kronberg 6014) and followed for 4-6 hours. The measurement was repeated at 30, 60, 120 minutes, and again 4-6 hours after the initial assessment.

RESULTS

The mean age of the patients was 47.8+/-41.1 months. The patients randomly received 15 mg/kg/dose of acetaminophen (n=112 group 1), 0.5 mg/kg/dose of ketoprofen (n=105, group 2), or 10 mg/kg/dose of ibuprofen (n=84, group 3). Fever was 38.4+/-0.7 degrees C, 38.4+/-0.7 degrees C, and 38.5+/-0.5 degrees C at 30 minutes; 38.0+/-0.7 degrees C, 37.9+/-0.7 degrees C, and 38.0+/-0.6 degrees C at 60 minutes (p>0.05), 37.7+/-0.6 degrees C, 37.6+/-0.7 degrees C, and 37.7+/-0.5 degrees C at 120 minutes (p>0.05); 37.5+/-0.7 degrees C, 37.3+/-0.6 degrees C, and 37.4+/-0.6 degrees C at 4-6 hours after admission (p>0.05). The fever was significantly lower at 30, 60, and 120 minutes in all group s (p<0.05). Early vomiting after medication (<6 hours) was observed in 3.8%, 13.5%, and 9.6% whereas late vomiting (6-48 hours) occurred in 1.3%, 2.7%, and 5.8% respectively (p>0.05). Bad taste was expressed by 5.1%, 12.2%, and 5.8% early (<6 hours), and 3.9%, 8.1%, and 3.8% late (6-48 hours) (p>0.05). There were no differences between age groups for antipyretic effect, taste and adverse effect in three drugs (p>0.05).

CONCLUSION

All three drugs were similar in terms of efficacy, adverse effects, and compliance within 48 hours of therapy. These results suggest that ketoprofen may be used for antipyresis as an alternative to acetaminophen and ibuprofen.

Guidelines on paediatric dosing on the basis of developmental physiology and pharmacokinetic considerations

The approach to paediatric drug dosing needs to be based on the physiological characteristics of the child and the pharmacokinetic parameters of the drug. This review summarises the current knowledge on developmental changes in absorption, distribution, metabolism and excretion and combines this knowledge with in vivo and in vitro pharmacokinetic data that are currently available. In addition, dosage adjustments based on practical problems, such as child-friendly formulations and feeding regimens, disease state, genetic make-up and environmental influences are presented. Modification of a dosage based on absorption, depends on the route of absorption, the physico chemical properties of the drug and the age of the child. For oral drug absorption, a distinction should be made between the very young and children over a few weeks old. In the latter case, it is likely that practical considerations, like appropriate formulations, have much greater relevance to oral drug absorption. The volume of distribution (V(d)) may be altered in children. Hydrophilic drugs with a high V(d) in adults should be normalised to bodyweight in young children (age <2 years), whereas hydrophilic drugs with a low V(d) in adults should be normalised to body surface area (BSA) in these children. For drugs that are metabolised by the liver, the effect of the V(d) becomes apparent in children <2 months of age. In general, only the first dose should be based on the V(d); subsequent doses should be determined by the clearance. Pharmacokinetic studies on renal and liver function clarify that a distinction should be made between maturation and growth of the organs. After the maturation process has finished, the main influences on the clearance of drugs are growth and changes in blood flow of the liver and kidney. Drugs that are primarily metabolised by the liver should be administered with extreme care until the age of 2 months. Modification of dosing should be based on response and on therapeutic drug monitoring. At the age of 2-6 months, a general guideline based on bodyweight may be used. After 6 months of age, BSA is a good marker as a basis for drug dosing. However, even at this age, drugs that are primarily metabolised by cytochrome P450 2D6 and uridine diphosphate glucuronosyltransferase should be normalised to bodyweight. In the first 2 years of life, the renal excretion rate should be determined by markers of renal function, such as serum creatinine and p-aminohippuric acid clearance. A dosage guideline for drugs that are significantly excreted by the kidney should be based on the determination of renal function in first 2 years of life. After maturation, the dose should be normalised to BSA. These guidelines are intended to be used in clinical practice and to form a basis for more research. The integration of these guidelines, and combining them with pharmacodynamic effects, should be considered and could form a basis for further study.

Ketoprofen and tramadol for analgesia during early recovery after tonsillectomy in children

BACKGROUND

Pain following tonsillectomy is often intense. Nonsteroidal anti-inflammatory drugs and opioids are effective, but both can cause adverse effects. Tramadol may be a viable alternative for post-tonsillectomy pain. This study was designed to compare the analgesic effects of ketoprofen and tramadol during the early recovery period after tonsillectomy.

METHODS

Forty-five ASA class I children (9-15 years) were randomized to receive either saline, ketoprofen (2 mg.kg(-1)) or tramadol (1 mg.kg(-1)) after induction of anesthesia. Upon completion of surgery, the study treatment was continued as a 6 h intravenous (i.v.) infusion of another dose of saline, ketoprofen (2 mg.kg(-1)) or tramadol (1 mg.kg(-1)). Postoperatively, each patient received rescue analgesia with patient-controlled analgesia (PCA) device programmed to deliver 0.5 microg.kg(-1) bolus doses of fentanyl. Postoperative pain was assessed using Visual Analog Scale (VAS) during swallowing. Intraoperative blood loss was measured.

RESULTS

The total number of requests of PCA-fentanyl was significantly less in ketoprofen group compared with tramadol and placebo groups (P = 0.035 and P = 0.049, respectively, in pairwise comparisons) and the VAS scores for pain were significantly lower in ketoprofen group compared with tramadol (P = 0.044) or placebo groups (P = 0.018) during the first six postoperative hours. Measured intraoperative blood loss was greater in ketoprofen-treated patients than in those receiving placebo (P = 0.029).

CONCLUSION

A dose of 4 mg.kg(-1) of i.v. ketoprofen provided good pain relief with moderate supplemental PCA-fentanyl requirements during the first six postoperative hours after tonsillectomy in children whereas the effects of 2 mg.kg(-1) of i.v. tramadol did not differ from those of placebo.

Bioavailability assessment of salbutamol sulfate suppositories in human volunteers

The purpose of this investigation was to evaluate the bioavailability of three salbutamol sulfate suppository formulations. The formulations were; 2 mg salbutamol sulfate in Suppocire NA base containing 6% Eudispert gel (F1), 2mg salbutamol sulfate in Witepsol H15 base containing 3% methyl cellulose gel (F2), and 2 mg salbutamol sulfate in Witepsol W25 base containing 3% methyl cellulose gel (F3). The formulations were administered via rectal route in six healthy male adult volunteers. The bioavailability of the three suppository formulations was compared with the oral bioavailability of salbutamol sulfate 2mg tablets (F4). Six volunteers participated in a four-way crossover study, where each study was separated from the other by an interval of 1 weak. Venous blood samples of 5 ml were taken immediately before dosing and after predetermined time intervals of 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6 and 8 h. The result showed that Cmax +/- S.D. observed were 12.96 +/- 2.11, 14.78 +/- 2.33, 10.02 +/- 1.42 and 11.51 +/- 1.22 ng ml(-1) for F1, F2, F3 and F4, respectively. The Tmax +/- S.D. were found to be 1.91 +/- 0.20, 1.83 +/- 0.26, 2.50 +/- 0.00 and 2.67 +/- 0.24 h for F1, F2, F3 and F4, respectively. AUC +/- S.D. values were 40.25 +/- 1.88, 42.16 +/- 1.55, 28.62 +/- 1.98 and 37.63 +/- 1.44 ng h per ml for F1, F2, F3 and F4, respectively. The relative bioavailabilities of the investigated formulations were 112.04, 106.96 and 76.06 for formula F2, F1 and F3, respectively, when compared with the oral preparation (F4). The finding indicates that the bioavailability of salbutamol sulfate can be enhanced by delivering it rectally with Suppocire NA base containing 6% Eudispert gel or with Witepsol W25 base containing 3% methyl cellulose to match that of oral tablets. Salbutamol sulfate can be rectally administered in patients who are less compliant with the oral administration.

Pharmacokinetics of Oxycodone After Intravenous, Buccal, Intramuscular and Gastric Administration in Children

OBJECTIVE

To evaluate the pharmacokinetics of four administration routes of oxycodone parenteral liquid (10 mg/mL), single intravenous and intramuscular injections and buccal and gastric administration, in children.

PATIENTS AND PARTICIPANTS

Forty generally healthy children, aged 6-93 months, undergoing inpatient surgery.

METHODS

After induction of anaesthesia, children received a single dose of oxycodone 0.1 mg/kg intravenously (n = 9), intramuscularly (n = 10), buccally (n = 11) or via an orogastric tube into the stomach (n = 10). Regular blood samples were collected up to 12 hours, and plasma was analysed for oxycodone using gas chromatography-mass spectrometry (limit of quantification 1 microg/L).

RESULTS

The peak drug concentration observed was 57-110 (mean 82) microg/L after intravenous administration, 23-54 (34) microg/L after intramuscular administration, 3.9-14 (9.8) microg/L after buccal administration and 1.7-15 (9.2) microg/L after gastric administration. The time to peak concentration was 2-30 (16) minutes in the intramuscular group, 30-480 (221) minutes in the buccal group and 60-360 (193) minutes in the gastric group. The terminal elimination half-lives were closely similar in the four groups: 124-208 (163) minutes in the intravenous group, 162-227 (150) minutes in the intramuscular group, 73-234 (150) minutes in the buccal group and 80-246 (147) minutes in the gastric group. Area under the concentration-time curve (AUC) was 5037-8954 (6612) microg x min/L in the intravenous group, 3084-5524 (4473) microg x min/L in the intramuscular group, 1444-5560 (3658) microg x min/L in the buccal group and 692-3843 (2436) microg x min/L in the gastric group. The estimated bioavailability (AUC/mean intravenous AUC) of intramuscular oxycodone was 0.47-0.84 (0.68), that of buccal oxycodone 0.22-0.84 (0.55) and that of gastric oxycodone 0.10-0.58 (0.37).

CONCLUSION

The pharmacokinetics of intravenous oxycodone in children aged 6-93 months are fairly similar to those reported in adults. Intramuscular administration provides relatively constant drug absorption, but after buccal and gastric administration the interindividual variation in the rate and extent of absorption is large.