Absorption pharmacokinetics of clonidine nasal drops in children

Intranasal Administration of a Polymeric Biodegradable Film to C57BL/6 Mice

Nasal drug delivery in rodents is a challenging procedure, especially for brain targeting, as the position of the material in the nasal cavity determines the success of the administration method. The objective of this study was to assess a novel intranasal administration technique for nose-to-brain delivery of biodegradable nasal films. The method was performed in C57BL/6 (n = 10; age, 8 wk) under inhaled sevoflurane. Twenty-four gauge catheters were used for the procedure. Hydroxypropyl methyl-cellulosebased film was formed in the lumen of the catheter and then delivered into the mouse nostril by pushing it out of the lumen using a trimmed and polished needle. Methylene blue was incorporated in the film-forming gel to indicate the delivery area in which the films were deposited. After administration, all mice recovered from anesthesia without incident. None of the mice showed any signs of injury, discomfort, or nose bleeding, thus allowing us to characterize the administration method as noninvasive. Furthermore, postmortem evaluation revealed olfactory-centered placement of the polymeric films, confirming the accuracy and repeatability of the method. In conclusion, this study documented the use of, a novel, noninvasive, intranasal administration technique for nose-to-brain drug delivery in biodegradable films for use in mice.

Comparison of different sedatives in children before general anaesthesia for selective surgery: A network meta-analysis

WHAT IS KNOWN AND OBJECTIVE

It is estimated that 60% of children undergoing anaesthesia develop severe preoperative anxiety. The anxiety is associated with adverse reactions. Sedatives such as dexmedetomidine, midazolam, clonidine, ketamine, and melatonin can be used as premedication against preoperative anxiety. However, no consensus has been reached on the choice of pre-anaesthetic sedatives in children before selective surgery. Therefore, the current network meta-analysis (NMA) was carried out to evaluate different sedatives in children aged between 1 and 7 before general anaesthesia for selective surgery.

METHODS

Randomized clinical trials (RCTs) were retrieved from Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases from inception to October 22, 2021. Primary outcomes showed satisfactory sedation at parent separation and also at induction or mask acceptance. Secondary outcomes were those related to added benefits and side effects. The present NMA was conducted using the R software. Results of the study were reported as Relative Risk (RR) or Mean Difference (MD) at a 95% credible intervals (CrIs).

RESULTS AND DISCUSSION

A total of 48 trials were included in the present study. It was found that the effectiveness of dexmedetomidine, midazolam, clonidine, and ketamine were superior to that of placebo in satisfactory sedation at parent separation and induction or mask acceptance. There was no significant difference between melatonin and placebo in satisfactory sedation at induction or mask acceptance. Dexmedetomidine, ketamine, clonidine, and melatonin were superior to placebo in reducing emergence delirium (ED). In addition, midazolam prolonged the length of stay in the post anaesthesia care unit (PACU) as compared with placebo. Dexmedetomidine caused a significant reduction in systolic blood pressure (SBP) and heart rate (HR). Nevertheless, it was noted that the hemodynamic changes were roughly within safety limits.

WHAT IS NEW AND CONCLUSION

It was evident that the studied drugs can provide effective sedation with exception of melatonin and placebo. However, it was found that midazolam, ketamine, and clonidine lead to several side effects. The findings of the present study supported that dexmedetomidine, especially intranasal administration, has potential in the optimal selection of the sedatives for premedication in children. This is because the drug has effective sedation, reduced incidence of ED, side effects, and onset time.

The use of clonidine in elderly patients with delirium; pharmacokinetics and hemodynamic responses

Background

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is an RCT investigating the effect of clonidine in medical patients > 65 years with delirium. To assess the dosage regimen and safety measures of this study protocol, we measured the plasma concentrations and hemodynamic effects of clonidine in the first 20 patients.

Methods

Patients were randomised to clonidine (n = 10) or placebo (n = 10). The treatment group was given a loading dose (75μg every 3rd hour up to a maximum of 4 doses) to reach steady state, and further 75μg twice daily until delirium free for 2 days, discharge or a maximum of 7 days. Blood pressure (BP) and heart rate (HR) were measured just before every dose. If the systolic BP was < 100 mmHg or HR < 50 beats per minute the next dose was omitted. Plasma concentrations of clonidine were measured 3 h after each drug intake on day 1, just before intake (day 2 and at steady state day 4–6) and 3 h after intake at steady state (C_max). Our estimated pre-specified plasma concentration target range was 0.3–0.7μg/L.

Results

3 h after the first dose of 75μg clonidine, plasma concentration levels rose to median 0.35 (range 0.24–0.40)μg/L. Median trough concentration (C₀) at day 2 was 0.70 (0.47–0.96)μg/L. At steady state, median C₀ was 0.47 (0.36–0.76)μg/L, rising to C_max 0.74 (0.56–0.95)μg/L 3 h post dose. A significant haemodynamic change from baseline was only found at a few time-points during the loading doses within the clonidine group. There was however extensive individual BP and HR variation in both the clonidine and placebo groups, and when comparing the change scores (delta values) between the clonidine and the placebo groups, there were no significant differences.

Conclusions

The plasma concentration of clonidine was at the higher end of the estimated therapeutic range. Hemodynamic changes during clonidine treatment were as expected, with trends towards lower blood pressure and heart rate in patients treated with clonidine, but with dose adjustments based on SBP this protocol appears safe.

Trial registration

ClinicalTrials.gov NCT01956604, 09.25.2013. EudraCT Number: 2013–000815-26, 03.18.2013. Enrolment of first participant: 04.24.2014.

A mini-review of non-parenteral clonidine preparations for paediatric sedation

Objective

To provide an overview of non-parenteral clonidine formulations and assess the feasibility of their use for paediatric sedation.

Methods

A literature search was conducted using electronic databases and a combination of search terms. Forty articles met the inclusion criteria. Publications were grouped into different dosage forms and assessed for their potential application for sedation of children in intensive care.

Key findings

Several routes of clonidine administration have been investigated for numerous indications in children, including perioperative sedation and analgesia. These include oral liquids, tablets, oral transmucosal systems, nasal sprays and rectal suspensions. Conflicting studies on oral transmucosal clonidine formulations suggest that further research is required to fully establish efficacy. Nasal sprays and rectal suspensions have the advantages of rapid onset of action and potential for dose flexibility, but predictable absorption is difficult to obtain.

Conclusions

Provided age-appropriate strengths are available, intravenous formulations remain the most predictable in terms of bioavailability and flexible in terms of dose adjustment. However, as with all routes, down-titration is difficult given the long half-life of clonidine. Oral transmucosal systems, nasal sprays and rectal suspensions have potential in a less acute setting, but significant clinical work is required to elucidate a full pharmacokinetic and pharmacodynamic profile.

The protocol of the Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID: a randomised placebo-controlled trial

Background

Delirium affects 15% of hospitalised patients and is linked with poor outcomes, yet few pharmacological treatment options exist. One hypothesis is that delirium may in part result from exaggerated and/or prolonged stress responses. Dexmedetomidine, a parenterally-administered alpha2-adrenergic receptor agonist which attenuates sympathetic nervous system activity, shows promise as treatment in ICU delirium. Clonidine exhibits similar pharmacodynamic properties and can be administered orally. We therefore wish to explore possible effects of clonidine upon the duration and severity of delirium in general medical inpatients.

Methods/Design

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is a randomised, placebo-controlled, double-blinded, parallel group study with 4-month prospective follow-up. We will recruit 100 older medical inpatients with delirium or subsyndromal delirium in the acute geriatric ward. Participants will be randomised to oral clonidine or placebo until delirium free for 2 days (Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria), or after a maximum of 7 days treatment. Assessment of haemodynamics (blood pressure, heart rate and electrocardiogram) and delirium will be performed daily until discharge or a maximum of 7 days after end of treatment. The primary endpoint is the trajectory of delirium over time (measured by Memorial Delirium Assessment Scale). Secondary endpoints include the duration of delirium, use of rescue medication for delirium, pharmacokinetics and pharmacodynamics of clonidine, cognitive function after 4 months, length of hospital stay and need for institutionalisation.

Discussion

LUCID will explore the efficacy and safety of clonidine for delirium in older medical inpatients.

Trial registration

ClinicalTrials.gov NCT01956604. EudraCT Number: 2013-000815-26

Intranasal clonidine vs. midazolam as premedication in children: a randomized controlled trial

OBJECTIVE

To compare anxiolysis produced by intranasal clonidine with intranasal midazolam as premedication in children undergoing surgery.

DESIGN

Double-blind randomized controlled study.

SETTING

Tertiary-care hospital, July 2009 to June 2010.

PATIENTS

60 American Society of Anesthesiologists physical status I-II surgical patients aged 1-10 yr.

INTERVENTION

Participants randomly allocated to receive either intranasal clonidine 4 mcg/kg (Group I) with atropine or intranasal midazolam 0.3 mg/kg (Group II).

OUTCOME MEASURES

Primary: satisfactory anxiolysis at 30 min after drug administration. Secondary: satisfactory mask acceptance, times of onset of sedation and anxiolysis, drug acceptance, level of sedation, wake-up score and side effects.

RESULTS

All children achieved satisfactory anxiolysis at 30 min. Group I fared significantly better than GroupII on mask acceptance (100% in Group I vs. 80% in Group II; P=0.024), drug acceptance (93% vs. 13%; P<0.001) and proportion of patients with satisfactory wake up scores (100% vs. 53%; P<0.001). Group II patients had significantly faster onset of sedation (median 10 min vs. 15 min; P<0.05) but not that of anxiolysis compared to Group-I (median 10 min for both groups; P>0.05). Side effects were significantly more frequent in Group II.

CONCLUSIONS

Though intranasal midazolam produced faster sedation, both the drugs produced satisfactory anxiolysis at 30 min.

Clonidine in the treatment of adolescent chronic fatigue syndrome: a pilot study for the NorCAPITAL trial

BACKGROUND

This pilot study (ClinicalTrials.gov ID: NCT01507701) assessed the feasibility and safety of clonidine in adolescent chronic fatigue syndrome (CFS). Specifically, we assessed clonidine dosage in relation to a) plasma concentration levels, b) orthostatic cardiovascular responses, and c) possible adverse effects.

FINDINGS

Five adolescent CFS patients (14-19 years old) received 50 μg clonidine twice per day during 14 days in an open, uncontrolled design. Plasma concentration of clonidine was assayed by standard laboratory methods. Changes in orthostatic cardiovascular responses were assessed by a 20o head-up tilt-test (HUT). Adverse effects were mapped by a questionnaire.After 14 days, C0 median (range) of clonidine was 0.21 (0.18-0.36) μg/L, and Cmax median (range) of clonidine was 0.41 (0.38-0.56) μg/L. Also, supine blood pressures and heart rate were lower during clonidine treatment, and the HUT response was closer to the normal response. No serious adverse effects were registered.

CONCLUSION

Clonidine 50 μg BID seems to be safe enough to proceed from a pilot study to a controlled trial in a select group of adolescents with CFS (ClinicalTrials.gov ID: NCT01040429).

Drug treatment of hypertensive crisis in children

Hypertensive crisis is a relatively rare event and is associated with significant morbidity and mortality in adults and pediatric patients alike. Rapid, safe, and effective treatment is imperative to alleviate immediate presenting clinical symptoms, prevent devastating morbidity, preserve long-term quality of life, and prevent mortality. Many medications in the hypertensive crisis arsenal have been used for nearly half a century. Nearly all treatment options have been utilized in children for decades, yet reliable data and sound clinical literature remain elusive. Every agent considered to be a first-line, second-line, or adjunctive option has yet to be evaluated in a randomized controlled trial in pediatric patients. With a paucity of clinical data to form evidence-based decisions, the clinician must rely entirely on the extrapolation from adult data and small retrospective studies, case series, and case reports of medication use in pediatric patients. Although more research in the treatment of pediatric hypertensive crisis is desperately needed, current practice demands a sharp knowledge of the pediatric clinical literature and pharmacology in this area as an essential tool to consistently improve patient outcomes with respect to morbidity and mortality.

Clonidine clearance matures rapidly during the early postnatal period: a population pharmacokinetic analysis in newborns with neonatal abstinence syndrome

The population pharmacokinetic (PK) profile of oral clonidine was characterized in newborns with neonatal abstinence syndrome, and significant covariates affecting its PK parameters were identified. Plasma clonidine concentration data were obtained from a clinical trial in which 36 newborns, aged 1 to 25 days (postnatal age, PNA) and weighing 2.1 to 3.9 kg, were enrolled to take multiple oral doses of clonidine. The population PK model of clonidine was developed by NONMEM, and significant covariates were identified, followed by nonparametric bootstraps (2000 replicates) and simulation experiments. A 1-compartment open linear PK model was chosen to describe plasma concentrations of clonidine, and body weight and PNA were significant covariates for apparent clearance (CL/F) as follows: CL/F (L/h) = 15.2 × [body weight (kg)/70](0.75) × [PNA (day)(0.441)/(4.06(0.441) + PNA (day)(0.441))]. Furthermore, CL/F of clonidine increased rapidly with PNA during the first month of life after body weight was adjusted. Any optimal dosage regimen for clonidine in term neonates should be based on infant's age and body weight, and 1.5 µg/kg every 4 hours is proposed starting the second week of life based on the simulation results.

The place of premedication in pediatric practice

Behind the multiple arguments for and against the use of premedication, sedative drugs in children is a noble principle that of minimizing psychological trauma related to anesthesia and surgery. However, several confounding factors make it very difficult to reach didactic evidence-based conclusions. One of the key confounding issues is that the nature of expectations and responses for both parent and child vary greatly in different environments around the world. Studies applicable to one culture and to one hospital system (albeit multicultural) may not apply elsewhere. Moreover, the study of hospital-related distress begins at the start of the patient's journey and ends long after hospital discharge; it cannot be focused completely on just the moment of anesthetic induction. Taking an example from actual practice experience, the trauma caused by the actual giving of a premedication to a child who absolutely does not want it and may struggle may not be recorded in a study but could form a significant component of overall effect and later psychological pathology. Clearly, attitudes by health professionals and parents to the practice of routine pediatric premedication, vary considerably, often provoking strong opinions. In this pro-con article we highlight two very different approaches to premedication. It is hoped that this helps the reader to critically re-evaluate a practice, which was universal historically and now in many centers is more selective.