Post by Mayleng on Dec 13, 2004 21:46:35 GMT -5
Here's some info I found on the Net which gives a good description of how some of the meds work.
Methylphenidate (Ritalin) is a short-acting medication. Ritalin SR, often seems to show inconsistent results.
Metadate-ER, manufactured by Celltech, was released in 10mg and 20mg sizes. Metadate-ER is similar to Ritalin-SR. The active component, methylphenidate, is in a wax-like matrix that releases the drug over time.
Celltech more recently released Metadate CD which uses a different delivery system. Its peak effect is generally around 5 hours and its effect lasts 8 hours. Metadate CD encapsulates the methylphenidate in two types of beads. About 30% of the medication is released immediately. The remainder is released over time through beads with a release-control membrane. If the individual cannot swallow the capsule, one can open it and sprinkle it on food.
Concerta (Alza Pharmaceuticals) is a form of Methylphenidate that uses an osmotic system to deliver methylphenidate in a pulsed pattern. This allows a 12 hour response from a single daily dose. Concerta was released in August 2000. The osmotic "oros" system has been used successfully for several years for a diabetes medication and a bladder control medication. Concerta's osmotic system involves a tri-layer inner core surrounded by a semi-permeable membrane with an immediate-release overcoat. This technology features a semi-permeable membrane surrounding an osmotic core, which contains a push layer and a drug layer. Once in the gastrointestinal tract, water enters the osmotic system and dissolves the drug in the core of the tablet. Osmotic pressure then causes the rate controlled release of the active drug through a laser-drilled hole in the membrane. With Concerta, the methylphenidate level starts relatively low and rises through most of the duration of the drug's action. Studies show that its usual duration of action is 12 hours, but there are a number of people who seem to get a shorter duration of effect at all dosage levels.
Novartis has released Ritalin-LA which is an improvement over the wax-like matrix delivery system used by Ritalin-SR. It encapsulates the active methylphenidate in microbeads. Half of the beads release the methylphenidate immediately. The other half of the beads are extended release. Ritalin LA is a good medication for those who experience Concerta as "too slow out of the blocks."
Novartis, the manufacturer of brand name Ritalin and Ritalin LA, also released a non-racemic form of methylphenidate, called Focalin. Other forms of methylphenidate such as Concerta and Metadate are mixtures of two mirror images (isomers) of the methylphenidate molecule. The body may metabolize the dextro (right handed) form of a compound differently from its mirror image the levo (left handed) form. In the case of methylphenidate, the dextro isomer is the active compound, and the levo form has minimal activity. Thus, Novartis recommends that when you switch from regular methylphenidate to Focalin, you start with half as much Focalin. Head to head studies do not show that Focalin is superior to a twice as big dose of Ritalin. However, some individuals experience it as lasting longer and causing less irritability when it wears off. Novartis is hoping to have FDA approval for a long-acting beaded delivery form of Focalin in 2005.
Slow Release amphetamines: Dexedrine Spansules, a long-acting form of d-amphetamine, has been on the market for years. It has a peak effect in 1-4 hours and lasts 6-10 hours. It tends to have a more gradual tapering and thus may have less of a rebound effect.
Adderall is a mixture of four salts of d-amphetamine combined with a smaller amount of the less active r-amphetamine. In November 2001, Shire, the manufacturer of Adderall, released Adderall XR. In this formulation, the Adderall is encapsulated in coated beads inside of a capsule. Half of the beads dissolve immediately, and the other half dissolve about 4-6 hours later. Adderall XR is useful for patients who cannot swallow pills. Shire has looked at the metabolism of Adderall XR when the capsule is opened and the beads are sprinkled on pudding.
Bupropion SR and XL (Wellbutrin) has been used to treat AD/HD for several years. A recent controlled study showed that it is effective in the treatment of AD/HD symptoms in adults. Its structure is chemically similar to amphetamine, but does not have the same abuse potential. It should not be used in individuals with bulimia or a seizure disorder.
Guanfacine (Tenex) acts in a manner similar to Clonidine (Catapress). Because Guanfacine lasts longer than Clonidine, only one or two doses are needed each day. Recent research confirmed that it can be useful in children, especially the 30% who have difficulty tolerating stimulants. Clonidine and Tenex seem particularly useful for impulsivity and aggression. Like Clonidine, Guanfacine can reduce tics for individuals with Tourette Syndrome. Since both Clonidine and Tenex can affect blood pressure and heart rate, it is a good idea to monitor blood pressure and get an EKG to check the heart rhythm. These medications can help all of the symptoms of AD/HD but often seem to help impulsivity motor hyperactivity and irritability more than attention. In some cases, Clonidine or Tenex is combined with a stimulant if the stimulant does not have enough effect on irritability and impulsivity.
Effexor and Effexor-XR (venlafaxine) An open trial (not a controlled study) with adults suggested that it might be helpful for some adults with AD/HD. In an open, 5-week study of children and adolescents with AD/HD, some individuals showed an improvement in behavioral but not cognitive measures. Several experienced worsening of their AD/HD symptoms and 25% could not tolerate the medication due to side effects. It is a good idea to monitor blood pressure since some individuals on Effexor show a rise in blood pressure. Sudden discontinuation of Effexor may lead to nausea and vomiting. Controlled studies of venlafaxine for AD/HD have not been as positive as the open uncontrolled data.
Mood Stabilizers are traditionally used for Bipolar Disorder. (Manic Depressive Disorder) These medications include Lithium and several anticonvulsant (seizure) medications such as Depakote (valproate) Tegretol (carbamazepine) and others. There is debate among psychiatrists about the percentage of AD/HD individuals who also have Bipolar Disorder. Some see the mood swings as part of the AD/HD. Others see it as a sign of a separate, co-existing disorder. In either case, the mood stabilizers may be useful to help modulate irritability and rapid mood shifts. These medications require closer medical monitoring. Blood tests and sometimes an EKG may be required. If an adult appears to have both AD/HD and Bipolar Disorder, one often treats the Bipolar Disorder first and then treats the AD/HD.
Atomoxetine, (Strattera) (formerly called tomoxetine) manufactured by Eli Lilly is the first non-stimulant to gain FDA approval for the treatment of AD/HD.
Modafinil (Provigil) has been approved for treatment of narcolepsy in adults. It is chemically unrelated to methylphenidate or amphetamine. When compared to methylphenidate and amphetamine, it seems less likely to cause irritability and jitteriness. It appears to act on the frontal cortex and is more selective in its area of action than the traditional stimulants. Cephalon will be doing studies to assess the efficacy of modafinil in children with ADHD. In studies of adults with ADHD, there was a promising study (Taylor and Russo) suggesting that it might be effective for adults with ADHD. However a larger study sponsored by Cephalon indicated that Modafinil was no more effective than placebo. Some of their studies have suggested a positive effect on children when larger doses are used. Cephalon is nearing completion of studies which will allow them to get an FDA approval for the use of modafinil in children with AD/HD.
Stimulant Medications: Duration of Action
Medication Frequency Peak Effect Duration of Action
Dexedrine d-amphetamine 2 or 3 times per day 1-3 hours 5 hours
Adderall 2 or 3 times per day 1-3 hours 5 hours
Dexedrine Spansules Once in am 1-4 hours 6-9 hours
Adderall XR Once in am 1-4 hours 9 hours
Ritalin 3 times per day 1-3 hours 2-4 hours
Focalin 2 times per day 1-4 hours 2-5 hours
Ritalin SR 1 or 2 times a day 3 hours 5 hours
Metadate CD Once in am 5 hours 8 hours
Concerta Once in am 8 hours 12 hours
Methylphenidate (Ritalin) is a short-acting medication. Ritalin SR, often seems to show inconsistent results.
Metadate-ER, manufactured by Celltech, was released in 10mg and 20mg sizes. Metadate-ER is similar to Ritalin-SR. The active component, methylphenidate, is in a wax-like matrix that releases the drug over time.
Celltech more recently released Metadate CD which uses a different delivery system. Its peak effect is generally around 5 hours and its effect lasts 8 hours. Metadate CD encapsulates the methylphenidate in two types of beads. About 30% of the medication is released immediately. The remainder is released over time through beads with a release-control membrane. If the individual cannot swallow the capsule, one can open it and sprinkle it on food.
Concerta (Alza Pharmaceuticals) is a form of Methylphenidate that uses an osmotic system to deliver methylphenidate in a pulsed pattern. This allows a 12 hour response from a single daily dose. Concerta was released in August 2000. The osmotic "oros" system has been used successfully for several years for a diabetes medication and a bladder control medication. Concerta's osmotic system involves a tri-layer inner core surrounded by a semi-permeable membrane with an immediate-release overcoat. This technology features a semi-permeable membrane surrounding an osmotic core, which contains a push layer and a drug layer. Once in the gastrointestinal tract, water enters the osmotic system and dissolves the drug in the core of the tablet. Osmotic pressure then causes the rate controlled release of the active drug through a laser-drilled hole in the membrane. With Concerta, the methylphenidate level starts relatively low and rises through most of the duration of the drug's action. Studies show that its usual duration of action is 12 hours, but there are a number of people who seem to get a shorter duration of effect at all dosage levels.
Novartis has released Ritalin-LA which is an improvement over the wax-like matrix delivery system used by Ritalin-SR. It encapsulates the active methylphenidate in microbeads. Half of the beads release the methylphenidate immediately. The other half of the beads are extended release. Ritalin LA is a good medication for those who experience Concerta as "too slow out of the blocks."
Novartis, the manufacturer of brand name Ritalin and Ritalin LA, also released a non-racemic form of methylphenidate, called Focalin. Other forms of methylphenidate such as Concerta and Metadate are mixtures of two mirror images (isomers) of the methylphenidate molecule. The body may metabolize the dextro (right handed) form of a compound differently from its mirror image the levo (left handed) form. In the case of methylphenidate, the dextro isomer is the active compound, and the levo form has minimal activity. Thus, Novartis recommends that when you switch from regular methylphenidate to Focalin, you start with half as much Focalin. Head to head studies do not show that Focalin is superior to a twice as big dose of Ritalin. However, some individuals experience it as lasting longer and causing less irritability when it wears off. Novartis is hoping to have FDA approval for a long-acting beaded delivery form of Focalin in 2005.
Slow Release amphetamines: Dexedrine Spansules, a long-acting form of d-amphetamine, has been on the market for years. It has a peak effect in 1-4 hours and lasts 6-10 hours. It tends to have a more gradual tapering and thus may have less of a rebound effect.
Adderall is a mixture of four salts of d-amphetamine combined with a smaller amount of the less active r-amphetamine. In November 2001, Shire, the manufacturer of Adderall, released Adderall XR. In this formulation, the Adderall is encapsulated in coated beads inside of a capsule. Half of the beads dissolve immediately, and the other half dissolve about 4-6 hours later. Adderall XR is useful for patients who cannot swallow pills. Shire has looked at the metabolism of Adderall XR when the capsule is opened and the beads are sprinkled on pudding.
Bupropion SR and XL (Wellbutrin) has been used to treat AD/HD for several years. A recent controlled study showed that it is effective in the treatment of AD/HD symptoms in adults. Its structure is chemically similar to amphetamine, but does not have the same abuse potential. It should not be used in individuals with bulimia or a seizure disorder.
Guanfacine (Tenex) acts in a manner similar to Clonidine (Catapress). Because Guanfacine lasts longer than Clonidine, only one or two doses are needed each day. Recent research confirmed that it can be useful in children, especially the 30% who have difficulty tolerating stimulants. Clonidine and Tenex seem particularly useful for impulsivity and aggression. Like Clonidine, Guanfacine can reduce tics for individuals with Tourette Syndrome. Since both Clonidine and Tenex can affect blood pressure and heart rate, it is a good idea to monitor blood pressure and get an EKG to check the heart rhythm. These medications can help all of the symptoms of AD/HD but often seem to help impulsivity motor hyperactivity and irritability more than attention. In some cases, Clonidine or Tenex is combined with a stimulant if the stimulant does not have enough effect on irritability and impulsivity.
Effexor and Effexor-XR (venlafaxine) An open trial (not a controlled study) with adults suggested that it might be helpful for some adults with AD/HD. In an open, 5-week study of children and adolescents with AD/HD, some individuals showed an improvement in behavioral but not cognitive measures. Several experienced worsening of their AD/HD symptoms and 25% could not tolerate the medication due to side effects. It is a good idea to monitor blood pressure since some individuals on Effexor show a rise in blood pressure. Sudden discontinuation of Effexor may lead to nausea and vomiting. Controlled studies of venlafaxine for AD/HD have not been as positive as the open uncontrolled data.
Mood Stabilizers are traditionally used for Bipolar Disorder. (Manic Depressive Disorder) These medications include Lithium and several anticonvulsant (seizure) medications such as Depakote (valproate) Tegretol (carbamazepine) and others. There is debate among psychiatrists about the percentage of AD/HD individuals who also have Bipolar Disorder. Some see the mood swings as part of the AD/HD. Others see it as a sign of a separate, co-existing disorder. In either case, the mood stabilizers may be useful to help modulate irritability and rapid mood shifts. These medications require closer medical monitoring. Blood tests and sometimes an EKG may be required. If an adult appears to have both AD/HD and Bipolar Disorder, one often treats the Bipolar Disorder first and then treats the AD/HD.
Atomoxetine, (Strattera) (formerly called tomoxetine) manufactured by Eli Lilly is the first non-stimulant to gain FDA approval for the treatment of AD/HD.
Modafinil (Provigil) has been approved for treatment of narcolepsy in adults. It is chemically unrelated to methylphenidate or amphetamine. When compared to methylphenidate and amphetamine, it seems less likely to cause irritability and jitteriness. It appears to act on the frontal cortex and is more selective in its area of action than the traditional stimulants. Cephalon will be doing studies to assess the efficacy of modafinil in children with ADHD. In studies of adults with ADHD, there was a promising study (Taylor and Russo) suggesting that it might be effective for adults with ADHD. However a larger study sponsored by Cephalon indicated that Modafinil was no more effective than placebo. Some of their studies have suggested a positive effect on children when larger doses are used. Cephalon is nearing completion of studies which will allow them to get an FDA approval for the use of modafinil in children with AD/HD.
Stimulant Medications: Duration of Action
Medication Frequency Peak Effect Duration of Action
Dexedrine d-amphetamine 2 or 3 times per day 1-3 hours 5 hours
Adderall 2 or 3 times per day 1-3 hours 5 hours
Dexedrine Spansules Once in am 1-4 hours 6-9 hours
Adderall XR Once in am 1-4 hours 9 hours
Ritalin 3 times per day 1-3 hours 2-4 hours
Focalin 2 times per day 1-4 hours 2-5 hours
Ritalin SR 1 or 2 times a day 3 hours 5 hours
Metadate CD Once in am 5 hours 8 hours
Concerta Once in am 8 hours 12 hours
This is a fantastic explaination!!
!!
snorkeler. Glad you like the article.
