Consider adverse drug events for any new symptom 

 Before adding a new therapy to the patient's drug regimen, clinicians should carefully consider whether the development of a new medical condition could be the presentation of an atypical adverse drug effect to an existing drug therapy. Many prescribing cascade scenarios have been identified

Consider nonpharmacologic approaches 

Some conditions in older adults may be amenable to lifestyle modification in lieu of pharmacotherapy. The Trial of Nonpharmacologic Interventions in the Elderly (TONE) demonstrated that weight loss and reduced sodium intake could allow discontinuation of antihypertensive medication in about 40 percent of the intervention group

Substitute with safer alternatives 

 When drug therapy is indicated for the older patient, it may be possible to substitute a safer alternative for the current regimen. As an example, in treatment of non-inflammatory arthritis, paracetamol may provide adequate pain relief and be a safer alternative to NSAIDs . Numerous studies have documented adverse events associated with NSAID use in older persons, including gastrointestinal bleeds , renal impairment , and heart failure

Reduce the dose 

 Many adverse drug events are dose-related. When prescribing drug therapies it is important to use the minimal dose required to obtain clinical benefit. Relative to those dispensed a low-dose, those dispensed a high-dose were more than twice as likely to develop parkinsonism .

Simplify the dosing schedule 

 When multiple medications are required, greater regimen complexity will increase the likelihood of poor compliance or confusion with dosing. Older adults, and particularly those with low health literacy, are not able to efficiently consolidate prescription regimens to optimize a dosing schedule. A standardized schedule for specifying medication dosing (morning, noon, evening, bedtime), recognises that 90 percent of prescriptions are taken four or fewer times daily .

Simplifying the medication dosing schedule, when possible, is also important in the long-term care setting where nursing staff and time requirements for medication administration are substantial. A study illustrated that within a seven-hour shift, on a 20-bed unit, with two scheduled periods of medication administration, the process of administering medications to the residents accounted for a third of the nursing time . This makes the nurse less available for other important patient care tasks.

Prescribe beneficial therapy 
The fewer-the-better approach to drug therapy in older adults is often not the best response to optimizing drug regimens. Avoiding medications with known benefits to minimize the number of drugs prescribed is inappropriate. Patients must be informed about the reason to initiate a new medication, and what the expected benefits are.

Discontinue unnecessary therapy 

Clinicians are often reluctant to stop medications, especially if they did not initiate the treatment and the patient seems to be tolerating the therapy. Sometimes, this exposes the patient to the risks for an adverse event with limited therapeutic benefit. 

The decision to discontinue medication is determined in part by the goals of care for that patient and the risks of adverse effects for that patient. Targets for treatment, based on outcomes evidence from studies in younger patients, may not be appropriate for older adults ; thus clinical guidelines not targeted to older patients may foster overly-aggressive goals for management of hypertension or diabetes in the older adult population.

Some preventive and other therapies may no longer be beneficial to patients with short life expectancies . The appropriateness of these therapies should be reconsidered when other medical conditions develop that impact a patient's long-term prognosis, unless the therapies are thought to increase comfort.

There are limited studies about how best to withdraw medications . It is reasonable to gradually taper off most medications to minimize withdrawal reactions and to allow symptom monitoring, unless dangerous signs or symptoms indicate a need for abrupt medication withdrawal. Certain common drugs require tapering, including beta blockers, opioids, barbiturates, clonidine, gabapentin, and antidepressants.

POLYPHARMACY 

 Polypharmacy is defined simply as the use of multiple medications by a patient. The precise minimum number of medications used to define “polypharmacy” is variable, but generally ranges from 5 to 10 . While polypharmacy most commonly refers to prescribed medications, it is important to also consider the number of over-the-counter and herbal/supplements used.

The issue of polypharmacy is of particular concern in older people who, compared to younger individuals, tend to have more disease conditions for which therapies are prescribed. It has been estimated that 20 percent of Medicare beneficiaries have five or more chronic conditions and 50 percent receive five or more medications .

The use of greater numbers of drug therapies has been independently associated with an increased risk for an adverse drug event, irrespective of age. There are multiple reasons why older adults are especially impacted by polypharmacy:

• Older individuals are at greater risk for adverse drug events due to metabolic changes and decreased drug clearance associated with aging; this risk is compounded by increasing numbers of drugs used.
• Polypharmacy increases the potential for drug-drug interactions.
• Polypharmacy was an independent risk factor for hip fractures in older adults in one case-control study, although the number of drugs may have been an indicator of higher likelihood of exposure to specific types of drugs associated with falls (eg, CNS active drugs) .
• Polypharmacy increases the possibility of “prescribing cascades” ... A prescribing cascade develops when an adverse drug event is misinterpreted as a new medical condition and additional drug therapy is then prescribed to treat this medical condition.
• Use of multiple medications can lead to problems with medication adherence, compounded by visual or cognitive compromise in many older adults.

A balance is required between over- and underprescribing. Multiple medications are often required to manage clinically complex older adults. Clinicians are often challenged with the need to match the complex needs of their older patients with those of disease-specific clinical practice guidelines. For a hypothetical older female patient with chronic obstructive pulmonary disease, type 2 diabetes, osteoporosis, hypertension and osteoarthritis, clinical practice guidelines would recommend prescribing 12 medications for this individual .

It is particularly important to reconsider medication appropriateness late in life. The process considers the patients’ remaining life expectancy and the goals of care in reviewing the need for existing medications and in making new prescribing decisions. For example, if a patient’s life expectancy is short and the goals of care are palliative then prescribing a prophylactic medication requiring several years to realize a benefit may not be considered appropriate. This is increasingly being recognized as an important consideration when managing individuals with advanced dementia . Additionally, therapeutic medications (eg, antibiotics for pneumonia) may not increase comfort or quality of life when palliative care is the objective 

How to calculate drug dosage accurately ?

The lack of basic maths skills can be a major problem when it comes to administering drugs to patients. Calculations are still a significant source of drug error.

Parenteral opiates are often relied on to manage acute pain in patients needing effective analgesia. But errors resulting in overdose of intravenous opiate can lead rapidly to respiratory depression. The opiate antagonist naloxone reverses opiate overdose and is usually needed quickly. However, this can cause confusion, because the product is prepared in micrograms. A small volume is involved, and the dose given needs to be titrated against response. 

Postoperatively, the epidural route is now common for infusions of opiate and local anesthetic. If opiates or, indeed, most drugs, have been calculated incorrectly, the consequences for patients can be serious. 

If given in too high concentrations, local anesthetic used in epidural infusions can cause extensive motor blockade, leading to immobility and pressure ulcers, which is distressing to the patient.

 Drug calculations
Drug calculations appear to be impossibly difficult, unless you break them down into small steps. They are vitally important to get right, yet they are so easy to get wrong. Look at some commonly used drug calculations and the way that mistakes can happen.

 Type A calculations
When the dose you want is not a whole ampoule.

 For example:

 - Prescription states 200mg (milligrams)

 - You have an ampoule of 500mg (milligrams) in 4ml (millilitres).

 What volume contains the dose you need?

 If you have an ampoule of 500mg in 4ml, and you need 200mg, it can appear to be a daunting calculation. The first step is to find out what volume contains 1mg (4/500) and then multiply it by how many mg you want (200).

In this instance:

 200mg x 4ml / 500mg = 1.6ml

 The common error here is to get it upside down, and divide what you’ve got by what you want. This fortunately gives you a stupid answer, which is obviously wrong, in this case 10ml. You already know that you need a fraction of an ampoule and not two and a bit ampoules, which highlights the error. 

To help make sure you get it the right way up, remember WIG:

 What you Want x what it’s In / What you’ve Got

 Converting units
All weights, volumes and times in any equation must be in the same units. With weights the unit changes every thousand. For example, you need 1000 micrograms (mcg) to make 1 milligram (mg) and 1000 milligrams to make one gram (g) (Box 2). 

Type B calculations
These are infusion rate calculations. 

For example: 

- Prescription states 30 mg/hour 

- You have a bag containing 250mg in 50ml 

Therefore, at what rate (ml/hr) do you set the pump? 

These are the same as type A calculations, only once you have worked out the volume that contains the amount of drug you need, you set the pump to give that amount per hour. 

In this instance, work out how many ml contain ONE mg of drug 

Using the WIG equation

 30 x 50 / 250 = 6ml 

Therefore the calculation shows that, to give 30mg per hour, the infusion pump rate would need to be set at 6ml per hour. 

This calculation is straightforward when the rate you want (30mg/hour) and the amount of the drug in the bag (250mg) are both in the same units (mg). 

However, if the infusion required that 600 micrograms were to be infused each hour instead, this would first need to be converted into mg before the infusion rate was calculated, that is, 600 micrograms = 0.6mg. 

The equation for infusion rate calculation is dose stated in prescription (milligrams per hour) times volume in syringe (in millilitres) divided by the amount in the syringe (in milligrams) equals the infusion rate (millilitres per hour), or:

 Dose (mg/hr) x volume in syringe (ml) / Amount in syringe (mg) = Infusion rate

 Type C calculations
Infusion rate is required, but dose is ‘mg per kg’. 

For example: 

- Prescription states 0.5mg/kg/hour 

- You have a bag of 250mg in 50ml 

- Your patient weighs 70kg. 

At what rate (ml/hr) do you set the pump? 

To do this calculation you still use the WIG equation as above, but with one extra step to work out the ‘what you want’.

 First you need to convert the mg per kg into total mg by multiplying it by the patient’s weight.

So for a person who weighs 70kg, 0.5mg per kg is the same as 35mg. Once you have calculated this, the infusion rate can be worked out as in the Type B calculations.

 In this instance:

 0.5mg/kg/hr x 70kg x 50ml / 250mg = 7ml/hr

 Type D calculations
Infusion rate required, but dose is in mg/kg/min.

 For example:

- Prescription states 0.5mg/kg/min 

- You have a syringe of 250mg in 50ml 

- Your patient weighs 70kg 

At what rate (ml/hr) do you set the pump? 

As before, you will need to calculate what you want by multiplying the amount per kg by the patient’s weight. In this case:

 0.5mg x 70kg = 35mg

This time, however, the prescription states the rate per minute. The pump demands that the rate be set in ml per hour, therefore the rate per minute will need to be converted before the equation can be completed, by multiplying 35 by 60; that is, 35mg/min (35 milligrams per minute) is converted to 2100mg/hr (2100 milligrams per hour).

 From here, once again we use the type B calculation to find the infusion rate, which as shown will be 420ml/hr.

 2100 x 50 / 250mg = 420ml/hr

 Type E calculations

 Infusion rate is required, but the dose is in mcg/kg/min. For example:

 - Prescription states 3 micrograms (mcg)/kg/min

 - You have a syringe of 100mg in 50ml

 - Your patient weighs 70kg.

 At what rate do you set the pump (ml/hr)?

 As before, what you want is calculated by multiplying the amount per kg by the patient’s weight, that is:

 3mcg/kg for a 70kg person is 210mcg.

 Next the prescription rate needs to be converted into rate per hour, that is,

 210mcg/min = 12 600mcg/hr

 The prescription is in micrograms, but in your syringe you have milligrams. Both need to be in the same units, so you must convert one to the other, in this case mcg to mg. 12 600mcg/hr is the same as 12.6mg/hr.

 The calculation is then as follows:

 12.6 x 50 / 100 = 6.3ml/hr

There are many factors taken into consideration when deciding a dose of drug - including age of the patient, weight, sex, ethnicity, liver and kidney function and whether the patient smokes. Other medicines may also affect the drug dose.

Dosage instructions are written on the doctor's prescription or hospital chart, and on the pharmacy label of a prescribed medicine. Dosage instructions are also found on the packaging and inserts of over-the-counter medicines.

Dosage and Administration of Drugs

The dose is the amount of drug taken at any one time. This can be expressed as the weight of drug (e.g. 500 mg), volume of drug solution (e.g. 10 ml, 2 drops), the number of dosage forms (e.g. 1 capsule, 1 suppository) or some other quantity .

The dosage regimen is the frequency at which the drug doses are given. Examples include 2.5 mL twice a day, one tablet three times a day, one injection every four weeks.

The total daily dose is calculated from the dose and the number of times per day the dose is taken.

The dosage form is the physical form of a dose of drug. Common dosage forms include tablets, capsules, creams, ointments, aerosols and patches. Each dosage form may also have a number of specialized forms such as extended-release, buccal, dispersible and chewable tablets. The strength is the amount of drug in the dosage form or a unit of the dosage form (e.g. 500 mg capsule, 250 mg/5 mL suspension).

The route of administration is the way the dosage form is given. The optimal dosage is the dosage that gives the desired effect with minimum side effects.

New malaria vaccine shows promise in clinical trials

Anew malaria vaccine, which is being developed in the US, has shown promising results in early stage clinical trials, scientists say. Researchers found that high doses of the vaccine protected 12 out of 15 patients from the disease. The vaccine involves injecting live but weakened malaria-causing parasites directly into patients to trigger immunity.

 The next critical questions will be whether the vaccine is durable over a long period of time and can the vaccine protect against all strains of malaria. The results were published in the journal Science

Biocon launches ALZUMAb for psoriasis patients in India

Biocon, Asia's premier biotechnology company, today announced the launch of its first in class novel biologic ALZUMAb (Itolizumab), the world’s first anti-CD6 monoclonal antibody to be introduced for treating patients with chronic plaque psoriasis, in India.

 ALZUMAb with a unique Mechanism of Action (MOA) offers superior safety and similar efficacy profile compared to other existing therapies, and has a long remission period with very low opportunistic infection rate. Psoriasis is a socially debilitating disease affecting 2-3 percent of world population