Drugs and drug administration in extreme environments

Reconstituted and frozen botulinum toxin A is as effective and safe as fresh for treating axillary hyperhidrosis: A retrospective study

The use of reconstituted and frozen left-over botulinum toxin A, for treatment of patients with axillary hyperhidrosis seems to be common practice in healthcare. Thus, the objective of this study was to investigate the efficacy and safety of frozen and thawed versus fresh reconstituted abobotulinum toxin (Dysport®) and onabotulinum toxin (Botox®) in the treatment of axillary hyperhidrosis. A retrospective study was conducted analysing efficacy and data from pre- and 24 weeks post-treatment questionnaires together with medical records of individuals with moderate to severe axillary hyperhidrosis. The patients had received fresh prepared botulinum toxin A in their right axilla while frozen and thawed botulinum toxin A had been administered in their left axilla. Treatment was conducted at our Hyperhidrosis Clinic, Umeå University Hospital, Sweden 2019-2021. Pre- and post-treatment questionnaires from 106 patients were analysed. The patients were 18 to 55 years old, with a mean age of 30.7 ± 9.9 years. No significant differences in patient-reported variables, Hyperhidrosis Disease Severity Scale and VAS 10-point scale, were found between the different preparations (frozen compared to fresh) for abobotulinum toxin and onabotulinum toxin, before treatment and at 6 months follow-up. Multivariable regression analysis resulted in no significant difference regarding side-effects between the preparations or brands of botulinum toxin. The findings of this study support our clinical experience that both abobotulinum toxin and onabotulinum toxin, reconstituted, frozen and thawed, seem to be as effective and safe as fresh prepared botulinum toxin when treating axillary hyperhidrosis. Our findings indicate that left-over preparations of abo- and onabotulinum toxins, stored and frozen for up to 6 months, is a cost-and time-effective way of handling botulinum toxin for treatment of axillary hyperhidrosis.

An absence of evidence breeds contempt: A qualitative study of health system stakeholder perceptions of the quality of medicines available in Senegal

Poor-quality medicines pose a significant challenge for health systems in low- to middle-income countries (LMICs),with recent deaths in multiple countries following ingestion of substandard cough syrups emphasising the need for quality-assurance of medicines in our increasingly interconnected global markets. Research also suggests that the source (country of manufacture) and type of medicine (generic/brand) are perceived to be associated with medicine quality. This study explores perceptions of medicines quality among national stakeholders of a medicines quality assurance system (MQAS) in sub-Saharan Africa. Through semi-structured interviews (n = 29) with managers from organisations responsible for the MQAS, public-sector doctors and nurses, and regulated private-sector pharmacists in three urban centres in Senegal in 2013. A thematic approach to analysis was undertaken with themes organised under three main categories, the source of drugs, the type of medicine, and medicines storage. A key emerging theme was the perception of the inferior quality of generic medicines, especially those produced in Asia and Africa, as they were lower in cost and thus believed to be less effective in alleviating symptoms than their brand versions. Medicines in Senegal's less regulated (informal) street markets were also thought to be of poor-quality as they were not subjected to national regulatory processes or stored appropriately, resulting in exposure to direct sunlight and high temperatures. In contrast, the interviewees expressed confidence in medicines quality within the regulated sectors (public and private retail pharmacies) attributed to stringent national medicines regulation, secure medicines supply chains and adequate technical capacity to survey and analyse for medicines quality. Also, the views expressed typically described a medicine's quality in terms of its effectiveness in alleviating the symptoms of ill health (efficacy of a medicine).These perceptions may have implications for developing national medicines policy, the procurement and supply of affordable medicines and consumers' decision-making when purchasing medicines. Indeed, a proclivity for supplying and purchasing more expensive brand medicines may act as a barrier to accessing essential medicines.

Risk factors for heat-related illnesses during the Hajj mass gathering: an expert review

Human exposure to a hot environment may result in various heat-related illnesses (HRIs), which range in severity from mild and moderate forms to life-threatening heatstroke. The Hajj is one of the largest annual mass gatherings globally and has historically been associated with HRIs. Hajj attracts over two million Muslim pilgrims from more than 180 countries to the holy city of Makkah, Kingdom of Saudi Arabia. Several modifiable and non-modifiable factors render Hajj pilgrims at increased risk of developing HRIs during Hajj. These include characteristics of the Hajj, its location, population, and rituals, as well as pilgrims' knowledge of HRIs and their attitude and behavior. Makkah is characterized by a hot desert climate and fluctuating levels of relative humidity. Pilgrims are very diverse ethnically and geographically, with different adaptations to heat. Significant proportions of the Hajj population are elderly, obese, and with low levels of fitness. In addition, many have underlying health conditions and are on multiple medications that can interfere with thermoregulation. Other factors are inherent in the Hajj and its activities, including crowding, physically demanding outdoor rituals, and a high frequency of infection and febrile illness. Pilgrims generally lack awareness of HRIs, and their uptake of preventive measures is variable. In addition, many engage in hazardous behaviors that increase their risk of HRIs. These include performing rituals during the peak sunshine hours with no sun protection and with suboptimal sleep, nutrition, and hydration, while neglecting treatment for their chronic conditions. HRIs preventive plans for Hajj should incorporate measures to address the aforementioned factors to reduce the burden of these illnesses in future Hajj seasons. Lessons from the Hajj can be used to inform policy making and HRIs preventive measures in the general population worldwide.

Dried Urine Spot Analysis for assessing cardiovascular drugs exposure applicable in spaceflight conditions

Cardiovascular pharmacological countermeasures will be required as a preventive measure of cardiovascular deconditioning and early vascular ageing for long term space travelers. Physiological changes during spaceflight could have severe implications on drug pharmacokinetics and pharmacodynamics (PK/PD). However, limitations exist for the implementation of drug studies due to the requirements and constraints of this extreme environment. Therefore, we developed an easy sampling method on dried urine spot (DUS), for the simultaneous quantification of 5 antihypertensive drugs in human urine: irbesartan, valsartan, olmesartan, metoprolol and furosemide analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), considering spaceflight parameters. This assay was validated in terms of linearity, accuracy, and precision with satisfactory results. There were no relevant carry-over, matrix interferences. The targeted drugs were stable in urine collected by DUS until 6 months at +21 °C, +4°C, -20 °C (with or without desiccants) and at 30 °C during 48 h. Irbesartan, valsartan and olmesartan were not stable at 50 °C during 48 h. This method was found to be eligible for space pharmacology studies in terms of practicality, safety, robustness and energy costs. It has been successfully implemented in space tests programs led in 2022.

Patient-friendly extemporaneous formulation of bisoprolol: application to stability and bioavailability studies

Community and hospital pharmacists always face the challenge to prepare oral liquid extemporaneous formulations to fit the needs of a specific patient population when commercial forms or the required strength is unavailable. This study was performed to prepare a stable patient-friendly oral liquid extemporaneous formulation of bisoprolol. Eight different extemporaneous formulations were prepared using various suspending agent(s). The in vitro dissolution of all extemporaneous formulations was examined. A comprehensive accelerated stability study was carried out to evaluate the adequate beyond-use date of the most optimized extemporaneous formulation. A validated ultra-performance liquid chromatography method was used for the analysis and quantification of bisoprolol in the accelerated stability and bioavailability studies. A group of eight healthy volunteers was enrolled in a two-way cross-over experimental design to study the bioavailability of the most optimized extemporaneous formulation. The pharmacokinetic parameters of bisoprolol were estimated. Extemporaneous suspension containing 0.5% w/v xanthan gum was easily prepared with a simple, natural, safe, sugar-free excipients. It achieved the best dissolution behavior among other extemporaneous suspensions. It was an easily pourable viscous suspension with no sedimentation. At least 98% of the initial concentration of bisoprolol remained throughout the 6-month study period in the selected suspension regardless of the storage conditions. There was no perceptible change in color, odor, or taste, and no noticeable microbial growth was observed in any sample. The selected formulation was bioequivalent to the commercial tablet in terms of the rate and extent of absorption. This research may be of great help during development of appropriate extemporaneous formulation of bisoprolol fumarate. The simple preparation method could be utilized to draw up a standard operating procedure (SOP) easy to use by different types of pharmacy settings.

Stability of Drugs Stored in Helicopters for Use by Emergency Medical Services: A Prospective Observational Study

STUDY OBJECTIVE

Drugs stored in rescue helicopters may be subject to extreme environmental conditions. The aim of this study was to measure whether drugs stored under the real-life conditions of a Swiss helicopter emergency medical service (HEMS) would retain their potency over the course of 1 year.

METHODS

A prospective, longitudinal study measuring the temperature exposure and concentration of drugs stored on 2 rescue helicopters in Switzerland over 1 year. The study drugs included epinephrine, norepinephrine, amiodarone, midazolam, fentanyl, naloxone, rocuronium, etomidate, and ketamine. Temperatures were measured inside the medication storage bags and the crew cabins at 10-minute intervals. Drug stability was measured on a monthly basis over the course of 12 months using high-performance liquid chromatography. The medications were considered stable at a minimum remaining drug concentration of 90% of the label claim.

RESULTS

Temperatures ranged from -1.2 °C to 38.1 °C (29.84 °F to 100.58 °F) inside the drug storage bags. Of all the temperature measurements inside the drug storage bags, 37% lay outside the recommended storage conditions. All drugs maintained a concentration above 90% of the label claim. The observation periods for rocuronium and etomidate were shortened to 7 months because of a supply shortage of reference samples.

CONCLUSION

Drugs stored under the real-life conditions of Swiss HEMS are subjected to temperatures outside the manufacturer's approved storage requirements. Despite this, all drugs stored under these conditions remained stable throughout our study. Real-life stability testing could be a way to extend drug exchange intervals.

Photomechanical Polymer Nanocomposites for Drug Delivery Devices

We demonstrate a novel structure based on smart carbon nanocomposites intended for fabricating laser-triggered drug delivery devices (DDDs). The performance of the devices relies on nanocomposites' photothermal effects that are based on polydimethylsiloxane (PDMS) with carbon nanoparticles (CNPs). Upon evaluating the main features of the nanocomposites through physicochemical and photomechanical characterizations, we identified the main photomechanical features to be considered for selecting a nanocomposite for the DDDs. The capabilities of the PDMS/CNPs prototypes for drug delivery were tested using rhodamine-B (Rh-B) as a marker solution, allowing for visualizing and quantifying the release of the marker contained within the device. Our results showed that the DDDs readily expel the Rh-B from the reservoir upon laser irradiation and the amount of released Rh-B depends on the exposure time. Additionally, we identified two main Rh-B release mechanisms, the first one is based on the device elastic deformation and the second one is based on bubble generation and its expansion into the device. Both mechanisms were further elucidated through numerical simulations and compared with the experimental results. These promising results demonstrate that an inexpensive nanocomposite such as PDMS/CNPs can serve as a foundation for novel DDDs with spatial and temporal release control through laser irradiation.

Temperature mapping in an air ambulance helicopter: Implications for the delivery of pre-hospital transfusion

BACKGROUND

Pre-hospital blood products, including freeze-dried plasma, are increasingly carried on air ambulance helicopters. The purpose of this study was to map the temperatures within a civilian air ambulance and consider the implications for pre-hospital transfusion.

MATERIALS AND METHODS

We conducted a single-site prospective observational study in the United Kingdom. Tinytag temperature data-loggers (Gemini, UK) were secured on to three locations throughout an air ambulance, and one was placed inside an insulated drug-pouch. Temperatures were monitored at 5-min intervals. Data were downloaded monthly and processed using R and MKT software to collate maximum, minimum, and day/night mean kinetic temperatures (MKTs). Blood was transported in Crēdo ProMed 4 containers (Peli Products, S.L.U) and monitored with QTA data-loggers (Tridentify, Sweden).

RESULTS

A total of 344,844 temperature recordings were made on 302 days during a 12-month period from January 2019. The external ambient temperatures varied seasonally from -7.1°C to 31.2°C, whereas internal temperatures ranged from -0.3°C to 60.6°C. The warmest area was alongside the left front-crew position (range 1.9-60.6°C, MKT 24.8°C). The lowest daytime MKT (16.9°C) and range (1.7°C-36.4°C) were recorded next to the patient stretcher. Temperatures ranged from 4.2°C to 40.1°C inside the insulated drugs-pouch, exceeding 25°C on 47 days (15%) and falling below 15°C on 192 days (63%) In contrast, thermally packed blood maintained a range of 2-6°C.

CONCLUSION

The temperatures within an air ambulance varied throughout the cabin and often exceeded the external ambient temperature. Appropriately selected thermal protection and monitoring is required for the successful delivery of pre-hospital transfusion, even in a temperate climate.

Medication Handling and Storage among Pilgrims during the Hajj Mass Gathering

We aimed to investigate the knowledge and practices of Hajj pilgrims regarding medication storage and handling during the Hajj mass gathering. In this cross-sectional study, adult pilgrims from 30 countries were interviewed using a structured questionnaire during the 2019 Hajj. The study enrolled 1221 participants with a mean age of 50.8 years (SD = 12.5, range = 18-98) and male:female ratio of 1.7:1. Most pilgrims were literate, 50.4% had a university or higher education, and 38% reported at least one underlying health condition. Most pilgrims reported receiving education regarding the proper way to store their medication during Hajj, mainly from physicians (73.7%) and pharmacists (39.4%). Although 68.2% of pilgrims had good knowledge regarding medication storage and the potential effect of inappropriate storage conditions on medications and health, inadequate knowledge and poor practice were identified among some. Level of education, having an underlying health condition and receiving health education on mediation storage were independently associated with good knowledge. Most pilgrims took their medications with them during Hajj, although storage and handling of their medication also varied depending on the stages of their Hajj pilgrimage journey. Improving Hajj pilgrims' awareness and knowledge about appropriate storage and handling of their medications are beneficial in reducing the risk of associated adverse health outcomes, both during Hajj and beyond the mass gathering.

Pharmakologische Eigenschaften von Notfallmedikamenten unter Extrembedingungen

Notfallmedikamente kommen an nahezu allen Orten dieser Erde zum Einsatz. Damit werden sie unterschiedlichsten Umweltbedingungen (Kälte, Hitze, direkte Sonneneinstrahlung) ausgesetzt. Sämtliche Daten zur Pharmakokinetik, Pharmakodynamik, Medikamentensicherheit und -haltbarkeit werden jedoch unter standardisierten Bedingungen erhoben, die sich von den Anwendungsbedingungen in der Notfallmedizin erheblich unterscheiden können. Durch die Kälte bei Wintereinsätzen im Gebirge können ebenso wie bei Einsätzen in großer Hitze und bei direkter Sonnenexposition chemische Reaktionen entstehen, welche die Eigenschaften der Medikamente bis hin zur kompletten Wirkungslosigkeit verändern können. Zusätzlich können Unterkühlung oder Überhitzung des Patienten zu einer Zentralisation bzw. Vasodilatation führen und damit das pharmakologische Verteilungsvolumen erheblich verändern, woraus Unter- bzw. Überdosierungen resultieren können. Gleichzeitig kann durch einen temperaturbedingt veränderten Metabolismus die Konjugation und Elimination von Medikamenten beeinflusst sein und zu einer unvorhersehbaren Verlängerung der Medikamentenwirkung führen. Trotz der erheblichen klinischen Relevanz dieser Thematik existieren bisher kaum Daten zu den konkreten Effekten extremer Umweltbedingungen auf die pharmakologischen Eigenschaften von Notfallmedikamenten. Diese Übersicht soll dazu dienen, den aktuellen Kenntnisstand der notfallmedizinischen Pharmakotherapie unter Extrembedingungen darzustellen.

Handling and packaging of medical bags at acute disaster sites under high-temperature conditions

OBJECTIVE

After the large-scale earthquake in 2011, the disaster medical assistance team (DMAT) was made responsible for medical activities during the hyperacute phase of a disaster or accident in Japan. The medicines to be administered at the disaster sites, packaged in medical bags, may be affected by the temperatures there. This study aimed at establishing a method to handle drug bags in high-temperature situations by determining the temperature changes in medical bags subject to high temperatures and examining the effect of opening the bag and using heat-insulating material (HIM) and coolants.

RESULTS

Closed and semi-opened bags limited the temperature increase in the central part of the bag at both 35 and 40 °C to a greater extent than opened bags. When coolant and HIM were used in closed and semi-opened bags, the internal temperatures were significantly lower than in the opened state at 40 °C. In high-temperature disaster sites, medical bags should be maintained in a semi-opened or closed state using a HIM and coolant.

[Epidemiology and prevention of heat-related adverse health effects on elderly people]

Heat waves increase the morbidity and mortality in Germany, particularly of older patients in need of care. Due to climate change the number of heat waves in Germany will increase threefold by the end of the century. In addition, the proportion of patients at risk will grow due to demographic change. Therefore, the Government and the Federal States have developed recommendations for heat action plans, in which the medical profession should also participate in the prevention of heat-related damage to health. Physicians and their team should first become acquainted with the topic. In addition, they should inform patients at risk and their relatives of the risks and preventive measures. In the summer a critical check of drugs is also needed because medications impair cooling mechanisms in heat waves, the pharmacokinetics can change and unwanted side effects of drugs occur more frequently. Lastly, due to their central position in the healthcare system, physicians should participate in the coordination of a good nursing care and intensification of social contacts during heat waves.

A study of temperature control in different designs of emergency drug transport bags

We investigated whether low melting point phase-change waxes could be incorporated into emergency drug transport bags to attenuate the known temperature extremes their contents can be exposed to. We exposed two custom-made hollow-walled drug containers placed within a pair of drug transport bags to three day/night cycles including periods of direct radiant sunlight. The wall cavities of one contained air, whereas those of the other contained a paraffin wax (melting point of 44-46 °C) with a high latent heat of fusion (until fully melted, its temperature does not increase further). We collected 25,920 temperature datasets at six locations. We found that 97.8% and 84.7% of ampoule temperatures within the wax and air cavity containers, respectively, were within a target range of 15-40 °C over the study duration (Levene statistic W = 4279.1; Levene's test for equality of variance, p < 0.001). Ampoule temperatures in the wax cavity container only exceeded 40 °C for 1.7% of the time. Even when they did so, their temperature was attenuated to 40.3 °C, despite an ambient air temperature of > 40 °C for 6.4% of the time (peak 46.9 °C) and a bag surface temperature of > 40 °C for 17.2% of the time (peak 64.4 °C). In contrast, the ampoule temperature in the air cavity container exceeded 40 °C for 17.1% of the time (peak 54.1 °C). The latent heat of fusion of phase-change materials may be exploited in the design of drug transport bags to mitigate any temperature changes in the drugs stored within them.

Temperature-sensitive Medications in Interfacility Transport: The Ice Pack Myth

INTRODUCTION

Critical Care Transport teams use various strategies to maintain temperature sensitive drugs and equipment at optimal temperature. The purpose of this study was to examine the effectiveness of current passive refrigeration of temperature sensitive transport medications/equipment.

METHODS

Initially, we performed a retrospective review of transport durations. Subsequently, an experimental paradigm was created using a temperature probe inside of the transport cooler packs utilizing various configurations and initial starting temperatures with high and low "in range" temperature margins of 8°C (max) and 2°C (min).

RESULTS

The mean round-trip transport time was 2.5 hours and over 15% of transports last longer than 4 hours. At a starting temperature of -3.9°C, the cooler and ice pack maintained "in range" temperatures for 3 hours. When the ice pack starting temperature was -12.9°C, high temperatures excursions weren't experienced until 6 hours 55 minutes, but initially low excursions fell below for up to 3 hours. iSTAT^® cartridges remained within range between 1-4 hours at cooler and ice pack starting temperature of -3.9°C.

CONCLUSION

The current system of passive refrigeration does not appear to be sufficient for safely storing medications or point-of-care testing equipment for our transport services. This might reveal a flaw in the existing practices around medication refrigeration in transport.

How to transport veterinary drugs in insulated boxes to avoid thermal damage by heating or freezing

BACKGROUND

The transport of veterinary drugs must comply with the general standards for drug storage. Although many vehicles are equipped with active heating and/or cooling devices assuring recommended storage conditions, simple insulated transport boxes are also often used. In this study, measurements for typical transport boxes were performed under laboratory conditions by the use of a climate chamber for a temperature of -20 °C and 45 °C to investigate the impact of box size, insulation material, liquid vs. dry filling products, filling degree and other parameters on the thermal performance of insulated boxes. Model calculations and instructions are presented to predict the retention time of recommended drug storage temperatures.

RESULTS

The measurements and the model calculations showed that the loading of the transport boxes with additional water bottles to increase the heat capacity is appropriate to prolong the retention time of the recommended temperature range of the drugs. Insulated transport boxes are not suitable to store drugs over a period of more than approximately 12 h. For practical use a recipe is presented to measure the thermal properties of a transport box and the related retention time for which the recommended storage temperatures can be assured.

CONCLUSIONS

The following principles for drug transportation in vehicles are recommended: (1) Before transfer into boxes, drugs should always be thermally preconditioned (2) Increase the filling degree of the boxes with thermally preconditioned water bottles or re-usable thermal packs will increase the heat capacity. Do not deep-freeze the bottles or packs below 0 °C to avoid drug freezing due to contact. (3) Open the lid of the boxes only to uncase drugs that are immediately needed. (4) The bigger the box and the higher the filling degree, the longer the retention time of the transport box. (5) Wherever possible, place the drug box at a cool site inside the vehicle. (6) The monitoring of the inside temperature of the transport boxes is recommended. By the proper use of such transport boxes the recommended temperatures can be maintained over one working day.

Mountain medical kits: epidemiology-based recommendations and analysis of medical supplies carried by mountain climbers in Colorado

OBJECTIVE

: To provide medical kit recommendations for short mountain wilderness recreation trips (hiking, trekking, backpacking, mountaineering etc.) based on the epidemiology of injury and illness sustained and best treatment guidelines. Additionally, to compare these recommendations to the medical kit contents of mountain climbers in Colorado.

METHODS

: A primary literature review concerning the epidemiology of injury and illness in mountain wilderness settings was performed. This information and literature on the efficacy of given treatments were used to derive recommendations for an evidence-based medical kit. The contents of 158 medical kits and the most likely demographics to carry them were compiled from surveys obtained from mountain climbers on 11 of Colorado's 14 000-foot peaks.

RESULTS

: Musculoskeletal trauma, strains, sprains and skin wounds were the most common medical issues reported in the 11 studies, which met inclusion criteria. Adhesive bandages (Band-Aids) were the most common item and non-steroidal anti-inflammatory drugs were the most common medication carried in medical kits in Colorado. More than 100 distinct items were reported overall.

CONCLUSION

: Mountain climbing epidemiology and current clinical guidelines suggest that a basic mountain medical kit should include items for body substance isolation, materials for immobilization, pain medications, wound care supplies, and medications for gastrointestinal upset and flu-like illness. The medical kits of Colorado mountain climbers varied considerable and often lacked essential items such as medical gloves. This suggests a need for increased guidance. Similar methodology could be used to inform medical kits for other outdoor activities, mountain rescue personnel, and travel to areas with limited formal medical care.

Hot and Cold Drugs: National Park Service Medication Stability at the Extremes of Temperature

STUDY OBJECTIVE

National Park Service (NPS) Parkmedics provide medical care in austere environments. The objective of this study was to evaluate the stability of specific medications used by Parkmedics at extremes of temperatures likely to be faced in the field.

METHODS

This is a bench research study conducted in the laboratory setting over a 4-week period. Parenteral medications were separated into 4 temperature exposure groups: A) 45°C (hot); B) -20°C (cold); C) hot then cold temperatures alternating weekly; and D) cold then hot temperatures alternating weekly. At study start and the end of each week, three aliquots from each group were sampled to determine the remaining drug concentration through liquid chromatography-quadrupole time-of-flight mass spectrometry (Agilent LC 1260- QTOF/MS 6550). Quantitative analysis was done using Agilent MassHunter Quantitative Analysis software. The mean drug concentration from triplicate aliquots was expressed as percentage of its baseline concentration to monitor the drug's stability during storage.

RESULTS

Eight medications were analyzed (atropine, diphenhydramine, fentanyl, hydromorphone, midazolam, morphine, naloxone, ondansetron). Hydromorphone, morphine, and ondansetron showed the greatest stability, at above 90% of original concentration in all study arms. Diphenhydramine, fentanyl and midazolam showed heat independent degradation, degrading the same way regardless of heat exposure. By the end of the study period, 51-56% midazolam remained in all groups. Atropine and naloxone showed heat dependent degradation, degrading more when exposed to heat. Atropine had the most degradation, being undetectable after 4 weeks of heat exposure.

CONCLUSIONS

We recommend that EMS providers replace atropine, naloxone, diphenhydramine, fentanyl, and midazolam frequently if they are practicing in low call volume or high-temperature environments. Further studies will be needed to determine if re-dosing midazolam, naloxone, and atropine is the appropriate clinical strategy in this setting if adequate clinical effect is not reached with a single dose.

A systematic review of epinephrine degradation with exposure to excessive heat or cold

BACKGROUND

Epinephrine is a lifesaving drug in the treatment of anaphylaxis and cardiac resuscitation. Current US storage recommendations are for controlled room temperature (20°C-25°C), with excursions permitted from 15°C to 30°C. Maintaining epinephrine within this required range is challenging, particularly for patients carrying autoinjectors and during storage in emergency vehicles.

OBJECTIVE

To study epinephrine degradation with extreme temperature exposure for epinephrine concentrations used in anaphylaxis and cardiac resuscitation.

METHODS

We searched the literature for all studies of epinephrine in sealed syringes, vials, or ampules in concentrations between 1:1,000 and 1:10,000, that measured epinephrine in samples exposed to temperatures above and/or below the recommended storage temperature compared with control samples.

RESULTS

Nine studies were included. Heat exposure resulted in epinephrine degradation but only with prolonged exposure. Constant heat resulted in more degradation. None of the studies that evaluated epinephrine exposure to extreme cold found significant degradation. None of the studies evaluating the effects of real-world temperature fluctuations detected significant degradation. Only 2 small studies (1 evaluating heat and 1 freezing) involved autoinjectors, and all 40 devices tested fired correctly.

CONCLUSION

Temperature excursions in real-world conditions may be less detrimental than previously suggested. Freezing and limited heat excursions did not result in epinephrine degradation. Refrigeration of epinephrine appears to reduce degradation. However, the effect of extreme temperatures, particularly freezing, on autoinjectors is not sufficiently well established. More research in needed at clinically relevant high temperatures, with limited exposure to heat, and involving autoinjector devices.

The effect of altitude on inhaler performance

The purpose of the study is to understand the effect of altitude on the performance of selected pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). A testing apparatus that created consistent breath profiles through the Alberta Idealized Throat was designed to test five pMDIs and two DPIs at altitudes of 670, 2450, 3260, and 4300 m. Both gravimetric and chemical assays were conducted to determine the in vitro lung dose. Additionally, spray duration and shot weight for pMDIs and device resistance for DPI were measured. There was no significant change in in vitro lung dose for any of the pMDIs tested. Shot weight and spray duration were unaffected. The device resistance of the DPIs decreased with increasing altitude and was successfully modeled as a function of ambient pressure. The in vitro lung dose of both DPIs showed no significant change when operated with an inhaler pressure drop of 4 kPa, but for the Bricanyl(®) Turbuhaler(®), a significant decrease occurred when matching the volumetric inspiratory flow rate to that of the baseline altitude.

[Effect of heat transfer in the packages on the stability of thiamine nitrate under uncontrolled temperature conditions]

To accurately predict the stability of thiamine nitrate as a model drug in pharmaceutical products under uncontrolled temperature conditions, the average reaction rate constant was determined, taking into account the heat transfer from the atmosphere to the product. The stability tests of thiamine nitrate in the three packages with different heat transfers were performed under non-isothermal conditions. The stability data observed were compared with the predictions based on a newly developed method, showing that the stability was well predicted by the method involving the heat transfer. By contrast, there were some deviations observed from the predicted data, without considering heat transfer in the packages with low heat transfer. The above-mentioned result clearly shows that heat transfer should be considered to ensure accurate prediction of the stability of commercial pharmaceutical products under non-isothermal atmospheres.

Critical care at extremes of temperature: effects on patients, staff and equipment

Modern travel and military operations have led to a significant increase in the need to provide medical care in extreme climates. Presently, there are few data on what happens to the doctor, their drugs and equipment when exposed to these extremes. A review was undertaken to find out the effects of 'extreme heat or cold' on anaesthesia and critical care; in addition, subject matter experts were contacted directly. Both extreme heat and extreme cold can cause a marked physiological response in a critically ill patient and the doctor treating these patients may also suffer a decrement in both physical and mental functioning. Equipment can malfunction when exposed to extremes of temperature and should ideally be stored and operated in a climatically controlled environment. Many drugs have a narrow range of temperatures in which they remain useable though some have been shown to remain effective if exposed to extremes of temperature for a short period of time. All personnel embarking on an expedition to an extreme temperature zone should be of sufficient physical robustness and ideally should have a period of acclimatisation which may help mitigate against some of the physiological effects of exposure to extreme heat or extreme cold. Expedition planners should aim to provide climatic control for drugs and equipment and should have logistical plans for replenishment of drugs and medical evacuation of casualties.

Characterization of Lidocaine Transdermal Patches from Natural Rubber Latex

The mucous liquid of Hevea brasiliensis or Para rubber tree, called natural rubber latex (NRL), composes of cis-1,4-polyisoprene which can form a patch under suitable formulation. In this study, blank and 5% lidocaine-loaded NRL patches were formulated and then characterized for physicochemical properties as well as evaluated in vitro drug release and stability. The patches were observed for their appearances. Surface morphology of the patches was investigated using a SEM. XRD was employed to study the crystallinity of the drug, the patch, and the drug-loaded patch. The extractions of lidocaine-loaded patches were analyzed for drug contents by HPLC. In vitro drug release study was performed using modified Franz diffusion cells. The patches at initial preparation and after kept at 4, 25, and 45 °C for 3 months were investigated for the stability determination. The results suggested that NRL could be used as a main component in pharmaceutical transdermal patches with acceptable physicochemical properties. Lidocaine-loaded NRL patches provided desirable drug release but high storage temperatures could age the patches resulting in darken color and lower release amount.

Effects of packaging and heat transfer kinetics on drug-product stability during storage under uncontrolled temperature conditions

To predict the stability of pharmaceutical preparations under uncontrolled temperature conditions accurately, a method to compute the average reaction rate constant taking into account the heat transfer from the atmosphere to the product was developed. The average reaction rate constants computed with taken into consideration heat transfer (κ(re) ) were then compared with those computed without taking heat transfer into consideration (κ(in) ). The apparent thermal diffusivity (κ(a) ) exerted some influence on the average reaction rate constant ratio (R, R = κ(re) /κ(in) ). In the regions where the κ(a) was large (above 1 h(-1) ) or very small, the value of R was close to 1. On the contrary, in the middle region (0.001-1 h(-1) ), the value of R was less than 1.The κ(a) of the central part of a large-size container and that of the central part of a paper case of 10 bottles of liquid medicine (100 mL) fell within this middle region. On the basis of the above-mentioned considerations, heat transfer may need to be taken into consideration to enable a more accurate prediction of the stability of actual pharmaceutical preparations under nonisothermal atmospheres.

Cough and dyspnoea of an asthmatic patient at Mt. Kilimanjaro: a difficult differential diagnosis

This case highlights the difficulties associated with the differential diagnosis of pulmonary symptoms in patients with pre-existing diseases in extreme environmental conditions. A 58-year-old man with child-onset allergic asthma developed dyspnoea and an acute non-productive cough during a trekking expedition on Mt. Kilimanjaro (5895m) in Tanzania. The symptoms were believed initially to be linked to the high altitude exposure (high altitude pulmonary oedema (HAPE) or high altitude cough) or his pre-existing asthma. However, he was later diagnosed correctly with a reinfection of Bordetella pertussis. Pertussis is a highly communicable disease with potentially serious medical consequences that could have affected all of the expedition members. The effectiveness of a pertussis vaccine declines 4-12 years after the vaccination. Thus, it is suggested that the status of immunisation against pertussis should be checked along with those of other infections prior to travel.

Bronchial asthma: advice for patients traveling to high altitude

This article examines the possibility of traveling to altitude for patients suffering from bronchial asthma. The mountain environment, the adaptations of the respiratory system to high altitude, the underlying patho-physiologies of asthma, and the recommendations for patients, according to altitude, are discussed. In summary, staying at low altitude has a significant beneficial effect for asthmatic patients, due to the reduction of airway inflammation and the lower response to bronchoconstrictor stimuli; for staying at moderate altitude, there is conflicting information and no clinical data; at high altitude, the environment seems beneficial for well-controlled asthmatics, but intense exercise and upper airway infections (frequent during trekking) can be additional risks and should be avoided. Further, in remote areas health facilities are often difficult to reach.

International emergency medicine: a review of the literature from 2006

The field of international emergency medicine (IEM) has grown rapidly over the past several decades, with a rise in the number of IEM fellowship positions, sustained growth in the international sections of major emergency medicine organizations, and an increase in the range of topics included under its rubric. One of the greatest obstacles to the continued growth of IEM remains the lack of a high-quality, consolidated, and easily accessible evidence base of literature. In response to this perceived need, members of the Emergency Medicine Residents' Association IEM Committee, in conjunction with members of the Society for Academic Emergency Medicine International Health Interest Group, embarked on the task of creating a recurring review of IEM literature. This article reviews 25 IEM research articles published in 2006. Research articles were selected for the review according to explicit, predetermined criteria that included both methodological quality and perceived impact of the research. It is the authors' hope that this annual review will act as a forum for disseminating best practices while also stimulating further research in the field of IEM.