ADHD Medications
While far from catastrophic, it is worth mentioning that there was a recent recall by some manufacturers of the ADHD stimulant medication Dextroamphetamine Sulfate. Dextroamphetamine, which also goes by the trade name Dexedrine or Dextrostat (by other manufacturers), is a relatively potent stimulant used to treat ADHD and anxiety disorders. ETHEX issued a release to the FDA on Tuesday October 15, 2008 about a recall of the 5 mg tablets of its version of the drug. Tests had shown that a sample of the medication contained oversized tablets that included a noticeably higher dosage than labeled (up to twice as high in some cases).
The good news surrounding this release is that no wholesalers or retailers of the drug have filed reports citing oversized tablets of the 5 mg of the drug (click here for a pictured link to this product). Additionally, the company manufactures 10 mg tablets of the same product, so even an accidental "double dose" (10 mg) of the medication does not exceed the dosing maximum for this particular product line. The frequency of negative side effects is often limited when total dosing is below 15 mg, and the drug typically does not result in severe reactions until around 30 mg (three times the "double dose") is taken.
Hypothetically speaking, an accidental overdose of Dextroamphetamine sulfate could cause an array of symptoms and side effects including an increased heart rate (tachycardia) and elevated blood pressure (hypertension). The risk is increased if antidepressants of the Monoamine Oxidase Inhibitor family (such as Selegiline, Zelapar capsules or transdermal Emsam patches) have been used within two weeks of the dextroamphetamine sulfate medications.
Aside from possible risks for those with current cardiovascular disorders, it is unlikely that any major side effects would occur from taking the occasional oversized capsule. Nevertheless, it raises the concern about medication dosing and how important knowledge regarding the dose-dependant effects of ADHD medications truly are. In a future post, we will explore how different doses of the same medication can often result in vastly different responses in a patient.
ADHD medications
Friday, October 17, 2008
Risperidone Boosts ADHD Stimulant Medication Effects
ADHD Medications
We often search the fine print for ADHD medication labels to see if there are potentially negative drug-drug interactions. However, an equally valid question may be: are there other medications which may boost or augment the effectiveness of an ADHD medication while keeping negative side effects to a minimum? The answer to this question appears to be "yes". We have seen in a previous post how ADHD medications and treatments can often overlap those of co-occurring disorders, such as in bedwetting. We have also seen how Atomoxetine (Strattera) can be an effective treatment option for ADHD and Tourette's. We have also explored the relative safety of ADHD stimulant medications taken during pregnancy. Now we will discuss is which medication strategies are effective for ADHD and comorbid conduct disorders and evaluate the relative safety of these medication combos.
The drug Risperidone (also referred to as Risperdal or Rispen), is a relatively new antipsychotic medication which was released in 1993 for adults and was approved in 2007 as a treatment option for both pediatric schizophrenia and pediatric bipolar disorders. A year prior to this, it was used as a potential treatment medication for pediatric autism. Given the fact that individuals with ADHD are more prone to exhibiting multiple symptoms of these disorders, Risperidone is a potential agent of interest for certain forms of ADHD.
A key study was done in 2004 by MG Aman and colleagues and was published in the Journal of Child and Adolescent Psychopharmacology, which focused on the effects of Risperidone when used in conjunction with other stimulant medications for treating ADHD in children of sub-average IQ's during a 6-week study period. Additionally, differences in behavioral disorders frequently seen alongside ADHD, such as Conduct Disorder (CD) and Oppositional Defiant Disorder (ODD) were also monitored by the study.
Although not a stimulant medication itself, the study's findings suggest that Risperidone may prove to be useful in augmenting these stimulant medications' effectiveness for these disorders or combinations of disorders. Additionally, results from the study suggest that Risperidone,by itself is often an effective treatment for hyperactivity and conduct disorders that often occur alongside ADHD. When combined with stimulants, the overall effectiveness is even greater.
Safety-wise, the study found that the use of Risperidone produced no noticeable change in the number of stimulant-related adverse drug effects. The three main ADHD stimulant medications used in the study were Methylphenidate, Pemoline, and Dextroamphetamine, with levels for each medication covering a wide dosage range. It is first important to note that while methylphenidate and dextroamphetamine are both considered to be relatively safe stimulant medications for treating ADHD, Pemoline (Cyclert) is known to be potentially harmful to the liver, and is typically used sparingly, often as a last resort among many physicians. What the study observed, however, is that risperidone, when taken alongside these stimulant medications, does not increase the number or severity of these side effects (Risperidone treatment did result in slightly more weight gain than the placebo controls, but the overall difference was small). This should be taken as good news for those concerned with the overall safety and effectiveness of combining stimulant and non-stimulant medications.
While ADHD stimulant medications and antipsychotic agents have different modes of action and different biological "targets", the results of this study suggest that the two types of medication are often able to work together and improve each other's effectiveness, while incurring minimal side effects. This suggests that for children with both ADHD and some type of oppositional or conduct disorder, prescribing Risperidone along with a stimulant medication such as Ritalin, Concerta or Dexedrine may be a highly effective and relatively safe treatment option.
ADHD medications
ADHD and Bedwetting
It's a classic problem that often puzzles parents of ADHD children. Why does my 13 year old still wet his bed? As it turns out, bed wetting, or enuresis, is a surprisingly common comorbid (co-occurring) disorder to ADHD. Other ADHD comorbid disorders that have been mentioned in previous posts include epilepsy and Tourette's Syndrome.
While there is some evidence that the two disorders share a common underlying cause (the lack of inhibitory behavior present in ADHD could span to poor muscle control), it is interesting to note that the comorbid disorder of bed wetting is connected most strongly to the Inattentive Subtype of ADHD (as opposed to the Hyperactive/Impulsive Subtype or the Combined Subtype).
Furthermore, the use of the tricyclic antidepressant drug Tofranil (Imipramine), which is often used to treat bladder control problems, has also been shown to be an effective medication for treating ADHD in some cases. We will explore this in a bit more detail in a later post, but it is important to remember that enuresis is an unusually common disorder in individuals with ADHD, especially with the Inattentive Subtype in particular. Given the fact that medications used to treat this co-occurring disorder are also sometimes useful in treating ADHD, it is my hope that other existing drugs may be further explored for their role in treating ADHD.
ADHD Medications
Thursday, October 16, 2008
Do ADHD Medications Cause Birth Defects?
ADHD Medications and Pregnancy
Due to the impulsive tendencies of adults with ADHD (currently thought to be as high as 4% of the general adult population), one would expect higher rates of unplanned pregnancies among this subgroup of the adult population. This is, in fact, often the case. As a result, it is worth investigating whether women with ADHD, who are often on medications are posing hazardous risks to their babies by taking these drugs during pregnancy. Although this area of ADHD medications and birth defects has not been studied extensively, here are some following observations and guidelines to go by:
Since some of the most common primary forms of ADHD medications are amphetamine-based stimulant drugs (such as Adderall), it is necessary to mention the fact that amphetamine usage during pregnancy has been shown to correlate with a reduction in birth weights of these children. However, other factors of growth, such as head size or birth length were unchanged, and the birth weight reduction amounts were often significantly less than a pound compared to newborns of non-users of amphetamines (or less than a 5% difference on average). Another relatively large study done primarily on the stimulant dextroamphetamine (Dexedrine), showed no significant difference in birth weights or the prevalence of birth defects.
For medications such as methylphenidate (Ritalin, Concerta), which is not an amphetamine but rather and amphetamine-like stimulant, no significant evidence has shown any connection to birth defects or lower birth weights. However, one study in which the mothers had taken methylphenidate alongside alcohol, cigarettes and other drugs showed higher rates of birth defects, mental impairments and reductions in birth sizes. However, this study had no adequate group of controls, so the effects of the ADHD drug itself could not be determined. Nevertheless, we must leave room for the possibility that this type of stimulant may worsen birth defects triggered by other maternal patterns of substance abuse.
Some other ADHD medications have not been explored in depth in human mothers, but have been investigated in other mammals. For example, in a study done on the non-stimulant ADHD medication Atomoxetine (Strattera) in pregnant rats, it was shown that weight reduction, impaired bone development, and lower offspring survival rates were tied to high levels of this drug. Of course, this was done on a different mammalian system at doses up to 30 times higher than the recommended optimal levels for humans (on a pound-for-pound basis). An even higher relative dose done on rabbits was shown to interfere with development of the circulatory system with the offspring. However, these levels were shown to be significantly over the relative toxic level of the drug in humans.
As a quick side note, I should mention that a small fraction of the population carries an uncommon form of the genetic region CYP 2D6, which, among other things, is connected to the metabolism or breakdown of the Atomoxetine drug. Individuals with this rare form (which can be determined by genetic screens), may be somewhat more at risk than their counterparts. However, individuals with this genetic form would often exhibit adverse effects to the medication early on, and would likely be placed on a different medicated treatment option.
Based on the overall dearth of information involving ADHD medications and pregnancy, we cannot arrive at any definite conclusions about their relative safety in pregnant or nursing mothers. However, if the connection between these medications and birth defects was significant, the results of some of the aforementioned studies would likely have been much more foreboding. As a result, the use of controlled and prescribed medications at appropriate doses are unlikely to pose any sort of major threat in pregnant or nursing mothers. Nevertheless, certain drugs, although much less common as primary modes of treatment for ADHD can be utilized if potential pregnancy or birth defects are a concern.
Medications such as Bupropion (Wellbutrin), have been shown to be useful in treating some forms of ADHD and may be especially effective for individuals who also suffer from depression or those who want to quit smoking. Unfortunately, one of the negative side effects of this medication is that it can increase the risk of seizures (for more information on ADHD and seizures, please check out this earlier post). Nevertheless, aside from some of these potential risks, it appears that Bupropion poses a noticeably smaller role than most stimulants in triggering birth defects.
Additionally, the drug Clonidine, which has shown to be effective in treating ADHD in several cases (especially those cases in which an ADHD comorbid disorder such as Tourette's Syndrome), is also less likely to cause birth defects than stimulants. Clonidine, which also goes by the brand names Catapres and Dixarit, is also used as a treatment for hypertension and can also be used in conjunction with stimulant medications to treat ADHD individuals. This is often done because of the sedative effects of the drug, which, when administered strategically before bedtime, can help calm things down a bit by offsetting the stimulant effects of other ADHD medications. One major caveat with Clonidine, however, is that sudden withdrawal or discontinuation of the drug can cause a rapid and dangerous spike in blood pressure. If Clonidine is to be discontinued, the individual must be gradually weaned off the drug to avoid these negative and harmful side effects.
It is my hope that some of this information will serve as good news to pregnant or soon-to-be pregnant individuals with ADHD. While the information contained here should never be a substitute for personal medical advice, I want you to leave with the fact that, at least as of now, the overall risks of birth defects or complications remain relatively low for most ADHD drugs. This is especially true when other non-prescribed chemical substances are avoided.
ADHD medications and Pregnancy
Tuesday, October 14, 2008
Medication Concerns Surrounding ADHD and Epilepsy
Medication strategies for ADHD Comorbid Disorders
ADHD medications
In a previous post, we briefly discussed the challenge of medicating ADHD with a common coexisting disorder, namely Tourette's Syndrome. We saw that conventional medications that are often used in the first line of treatment for ADHD are often counterproductive if they make the accompanying disorders worse. Additionally, certain ADHD medications can pose increase risks or dangers to some of these co-occurring disorders. Several articles have been published on stimulant medications and their overall effectiveness and safety for epileptic patients. In this post, we will examine some of the strategies and concerns associated with treating Epilepsy occurring alongside of ADHD. We will tackle some of these medication questions in the second half of the post. However, in order to do this, however, we must first begin by discussing some relevant information surrounding the range, severity and diversity of the symptoms and underlying causes of these two disorders.
Like Tourette's, the disorder of Epilepsy also finds itself to be overlapping (or "comorbid") with ADHD. According to a study reported in the journal Archives of Disease in Childhood in 2005 done by Tan and Appleton, over 20% of individuals diagnosed with epilepsy have multiple symptoms of ADHD. Epilepsy, which is characterized by the presence of recurring seizures that are not provoked by external chemical or environmental triggers, is potentially the most dangerous comorbid disorder associated with ADHD. Further complicating this combination of disorders is the fact that a number of independent studies have linked stimulant drugs (which are often the primary mode of treatment for ADHD) to lowering threshold levels for seizures. As a precaution, stimulants such as methylphenidate are often avoided whenever possible in seizure-prone individuals.
However, relatively new evidence has shown that this may not necessarily be the case with regards to ADHD and comorbid epilepsy. It is important to note that a large number of studies linking stimulant ADHD medications to increased rates of seizures involved more "anecdotal" evidence of symptoms based on relatively small, non-random samples of individuals. While this information should not discredit the validity of these studies, it is important to realize that these studies do not carry the same amount of scientific "weight" as those of larger, randomized, population-based clinical trials.
Further complicating the issue is the fact that there are multiple subtypes, classifications and severity levels of epilepsy. For example, one of the milder forms of pediatric epilepsy is called CAE. CAE, which is short for Childhood Onset Absence Epilepsy, is characterized by short periods (typically less than 10 seconds) of lapses in consciousness, and is often accompanied by rapid or twitching eye movements. Unlike more severe cases of epilepsy, CAE is followed by an immediate full recovery in the individual. These short lapses, when not noticed or carefully observed are sometimes erroneously misread as ADHD since they do temporarily shut down memory, focus and attention, mimicking common ADHD traits.
Since the two disorders typically involve a completely different set of chemical signals, CAE individuals erroneously medicated for ADHD will naturally see little improvement with regards to either disorder. Of course, most competent trained professionals should easily be able to differentiate between the two (CAE episodes can typically be triggered and observed by inducing hyperventilation in a clinical setting, so a non-CAE individual with ADHD can quickly be separated out by this common procedure). Nevertheless, I feel that this possible misdiagnosis can be overlooked and is still worth mentioning. Also of interest in observing these two disorders is the fact that there is a gender bias for each one, although the biases are skewed in opposite directions. ADHD is seen much more often in boys than in girls (some medical professionals claim this ratio to be as high 4 to 1), while CAE is seen more frequently in girls.
Another common (and typically benign) form of epilepsy is called Centrotemporal or Rolandic Spikes. This form is often associated more with lack of facial control (partial facial paralysis and drooling), and physical speech impairments. It is believed that brain activity in many of these individuals, especially between episodes, is connected to a reduced attention span, similar to that of an ADHD individual.
Muddying this issue even further is the fact that these spikes are frequently seen in individuals who fall within the spectrum of autism. While diagnostic methods prohibit an individual from being concurrently labeled as both "ADHD" and "Autistic" (i.e., diagnostic criteria can only allow an individual to be labeled as one or the other but not both), it is important to note the large overlap of symptoms between the two. In other words, we have seen three disorders that all share a number of common overlapping symptoms.
These three disorders may even share a common genetic background. A genetic region on the 3rd chromosome identified as NHE9, has been suggested as having a possible association with ADHD. Another nearby region on the same chromosome has been tied to both autism and epilepsy, suggesting a strong possibility that all three disorders are at least in part tied down to a common genetic region. Since all three disorders are unique and often involve completely different sets of medications, it is easy to see that a misdiagnosis followed by a "mis-medication" can have profoundly negative consequences. With regards to this post, this means that individuals who do have ADHD and (appropriately) take stimulant medications may still see a relatively high frequency of epileptic symptoms, but these are often due to a common (and potentially genetic) underlying condition, and are often not due to the actual stimulant medications being administered for ADHD.
While there is the possibility of genetic overlap between ADHD and epilepsy, the two disorders typically follow completely different chemical pathways. ADHD is closely tied to two neuro-chemical signaling agents called dopamine and norepinephrine (also called noradrenaline), while epilepsy is typically tied to the neurochemicals Gamma Aminobutyric Acid (GABA), as well as Glutamic Acid and Aspartic Acid (both of which are dietary amino acids, and are chemically similar to the questionable food flavoring MSG). Nevertheless, it is true that stimulant medications that are used to treat ADHD (such as Concerta or Ritalin), have been shown to counteract the effectiveness of some traditional anti-seizure medications, namely phenobarbitone (also referred to as BAN, Luminal or phenobarbital). However, these earlier-version anti-seizure medications are often replaced by newer Anti-Epileptic Drugs (AED's), most of which don't have these negative drug interactions.
Additionally, several studies have actually pointed towards ADHD stimulant medications helping with seizure-potentiating conditions. For example, in a 1992 article in the Journal of Clinical Psychiatry, Wroblewski and coworkers observed that seizure-prone individuals with brain injuries actually saw a reduction in the number of episodes following the administration of the common ADHD stimulant methylphenidate. However, other related studies have failed to support these results.
Finally, it is also important to at least mention the possibility that stimulant medications used to treat ADHD may trigger seizures due to their well-known effects on the sleep cycle. While the exact causes of epileptic seizures are still unknown, it is worth mentioning that around half of these episodes occur either during or around periods of sleep. Additionally, sleep deprivation has been shown to increase the likelihood of seizures. It is my personal belief that we should never downplay these important facts and observations.
What I have really hoped to accomplish in this post is to provide you with a bit more background info surrounding ADHD stimulant medications and how some of the data connecting these drugs to increased seizures and epileptic episodes were acquired. Nevertheless, this was not meant to refute all claims that there is an increase risk of epilepsy that is involved by taking these medications, especially for those prone to seizures. Caution and careful monitoring by your physician are still paramount. It is my hope, and my main objective to simply arm you with a bit more information about these drugs, how they work, and how these common ADHD prescription medications can interfere with comorbid disorders such as epilepsy. Look for future posts for more "special cases" involving ADHD and other accompanying disorders.
ADHD medications
Subscribe to:
Comments (Atom)