Tricyclic antidepressants also boost norepinephrine and can cause a rise in dopamine neurotransmission, too. Personally, I think I lack dopamine, but will have tests done before I try anything, to see if anything is deficient. Sorry about the length of this, but thought someone might be interested.....
This is from Stahl's Essential Psychopharmacology Online:
http://stahlonline.cambridge.org/prescribers_drug.jsf?page=0521683505c25_p147-15...
Doxepin
Brands
* Sinequan
* see index for additional brand names
Generic?
* Yes
Class
* Tricyclic antidepressant (TCA)
* Serotonin and norepinephrine/noradrenaline reuptake inhibitor
Commonly Prescribed For
* (bold for FDA approved)
* Psychoneurotic patient with depression and/or anxiety
* Depression and/or anxiety associated with alcoholism
* Depression and/or anxiety associated with organic disease
* Psychotic depressive disorders with associated anxiety
* Involutional depression
* Manic-depressive disorder
* Pruritus/itching (topical)
* Dermatitis, atopic (topical)
* Lichen simplex chronicus (topical)
* Anxiety
* Insomnia
* Neuropathic pain/chronic pain
* Treatment-resistant depression
How The Drug Works
At antidepressant doses:
* Boosts neurotransmitters serotonin and norepinephrine/noradrenaline
* Blocks serotonin reuptake pump (serotonin transporter), presumably increasing serotonergic neurotransmission
* Blocks norepinephrine reuptake pump (norepinephrine transporter), presumably increasing noradrenergic neurotransmission
* Presumably by desensitizes both serotonin 1A receptors and beta adrenergic receptors
* Since dopamine is inactivated by norepinephrine reuptake in frontal cortex, which largely lacks dopamine transporters, doxepin can thus increase dopamine neurotransmission in this part of the brain
* May be effective in treating skin conditions because of its strong antihistamine properties
At low doses (1-6 mg/day):
* Selectively and potently blocks histamine 1 receptors, presumably decreasing wakefulness and thus promoting sleep
How Long Until It Works
* May have immediate effects in treating insomnia or anxiety
* Onset of therapeutic actions usually not immediate, but often delayed 2-4 weeks
* If it is not working within 6-8 weeks for depression, it may require a dosage increase or it may not work at all
* May continue to work for many years to prevent relapse of symptoms
If It Works
* The goal of treatment of depression is complete remission of current symptoms as well as prevention of future relapses
* The goal of treatment of insomnia is to improve quality of sleep, including effects on total wake time and number of nighttime awakenings.
* The goal of treatment of chronic neuropathic pain is to reduce symptoms as much as possible, especially in combination with other treatments
* Treatment of depression most often reduces or even eliminates symptoms, but not a cure since symptoms can recur after medicine stopped
* Treatment of chronic neuropathic pain may reduce symptoms, but rarely eliminates them completely, and is not a cure since symptoms can recur after medicine is stopped
* Continue treatment of depression until all symptoms are gone (remission)
* Once symptoms of depression are gone, continue treating for 1 year for the first episode of depression
* For second and subsequent episodes of depression, treatment may need to be indefinite
* Use in anxiety disorders, chronic pain, and skin conditions may also need to be indefinite, but long-term treatment is not well studied in these conditions
If It Doesn’t Work
* Many depressed patients only have a partial response where some symptoms are improved but others persist (especially insomnia, fatigue, and problems concentrating)
* Other depressed patients may be nonresponders, sometimes called treatment-resistant or treatment-refractory
* Consider increasing dose, switching to another agent or adding an appropriate augmenting agent
* Consider psychotherapy
* Consider evaluation for another diagnosis or for a comorbid condition (e.g., medical illness, substance abuse, etc.)
* Some patients may experience apparent lack of consistent efficacy due to activation of latent or underlying bipolar disorder, and require antidepressant discontinuation and a switch to a mood stabilizer
* If Insomnia does not improve after 7-10 days, it may be a manifestation of a primary psychiatric or physical illness such as obstructive sleep apnea or restless leg syndrome, which requires independent evaluation
Best Augmenting Combos for Partial Response or Treatment-Resistance
* Lithium, buspirone, thyroid hormone (for depression)
* Trazodone, GABA-ergic sedative hypnotics (for insomnia)
* Gabapentin, tiagabine, other anticonvulsants, even opiates if done by experts while monitoring carefully in difficult cases (for chronic pain)
Tests
* None for healthy individuals
* Since tricyclic and tetracyclic antidepressants are frequently associated with weight gain, before starting treatment, weigh all patients and determine if the patient is already overweight (BMI 25.0–29.9) or obese (BMI ≥30)
* Before giving a drug that can cause weight gain to an overweight or obese patient, consider determining whether the patient already has pre-diabetes (fasting plasma glucose 100–125 mg/dL), diabetes (fasting plasma glucose >126 mg/dl), or dyslipidemia (increased total cholesterol, LDL cholesterol and triglycerides; decreased HDL cholesterol), and treat or refer such patients for treatment including nutrition and weight management, physical activity counseling, smoking cessation, and medical management
* Monitor weight and BMI during treatment
* While giving a drug to a patient who has gained >5% of initial weight, consider evaluating for the presence of pre-diabetes, diabetes, or dyslipidemia, or consider switching to a different antidepressant
* EKGs may be useful for selected patients (e.g., those with personal or family history of QTc prolongation; cardiac arrhythmia; recent myocardial infarction; uncompensated heart failure; or taking agents that prolong QTc interval such as pimozide, thioridazine, selected antiarrhythmics, moxifloxacin, sparfloxacin, etc.)
* Patients at risk for electrolyte disturbances (e.g., patients on diuretic therapy) should have baseline and periodic serum potassium and magnesium measurements